Information storage medium, recording method, reproducing method, and reproducing apparatus

ABSTRACT

An information layer  0  comprises a system lead-in area, data lead-in area, data area, and middle area, an information layer  1  comprises a system lead-out area, data lead-out area, data area, and middle area, an end position of the data area of layer  1  is positioned outer than a start position of the data area of layer  0,  the data lead-in area comprises a guard track zone wider than a test zone in the data lead-out area, the data lead-out area comprises a guard track zone wider than a test zone and a management zone in the data lead-in area, the middle area of layer  0  comprises a guard track zone wider than a test zone in the middle area of layer  1,  and the middle area of layer  1  comprises a blank zone wider than a test zone in the middle area of layer  0.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2005-266016, filed Sep. 13, 2005, theentire contents of which are incorporated herein by reference.

BACKGROUND

1. Field

One embodiment of the invention relates to a storage medium such as arecordable optical disc, a recording method, and a reproducingapparatus.

2. Description of the Related Art

As recording media capable of recording a large quantity of informationsuch as video signals, digital versatile discs (DVDs) have beenpopularized. Consequently, a movie of about two hours is recorded on aDVD, and information is reproduced by a reproducing apparatus, whichmakes it possible to freely watch the movie at home. In recent years,digitization of television broadcasting has been proposed, and a planhas been made to put a high-resolution television system which is calleda high-definition television (HDTV) system to practical use. For thatpurpose, a standard for a next-generation DVD has been proposed in whicha recording capacity is increased by narrowing down a beam spot, forexample, in such a manner that a wavelength of a laser beam isshortened, or a numerical aperture NA is enlarged. As a technique ofincreasing a recording capacity, use of a single-sided multilayerrecording medium has been considered in addition to the method ofnarrowing down a beam spot. The single-sided multilayer recording mediumis configured such that a plurality of recording layers are provided onone side of a disc, and a beam is focused on the respective layers bymoving an objective lens in an optical axis direction, which makes itpossible to write/read for each recording layer (for example, refer toJpn. Pat. Appln. KOKAI Publication No. 2004-206849, paragraphs 0036 to0041, FIG. 1)

A single-sided multilayer information recording medium has the problemof interlayer crosstalk which is not generated in a single-sidedsingle-layer recording medium. For ease of explanation, dual layers willbe described as an example. In a single-sided dual layer recordingmedium, a laser beam is focused on the respective layers from a singleread surface. A layer close to the read surface is called Layer 0, and alayer distant from the read surface is called Layer 1. When a beam isfocused on each layer, some laser beam is irradiated onto a layer otherthan a target layer. For this reason, a reflected light from the layerother than the target layer is mixed up with a reproduction signal inreproduction, which brings about interlayer crosstalk. Note thatinterlayer crosstalk could be a problem in, not only reproduction, butalso recording.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A general architecture that implements the various feature of theinvention will now be described with reference to the drawings. Thedrawings and the associated descriptions are provided to illustrateembodiments of the invention and not to limit the scope of theinvention.

FIG. 1 is an exemplary view of the contents of constituent elements ofan information storage medium and a combination method in the presentembodiment;

FIGS. 2A and 2B are exemplary views showing a standard phase shiftrecording film structure and an organic dye recording film structure;

FIG. 3 is an exemplary view showing a specific structural formula of thespecific content “(A3) azo-metal complex+Cu” of the information storagemedium constituent elements shown in FIG. 1;

FIG. 4 is an exemplary view illustrating an example of opticalabsorption spectrum characteristics of an organic dye recording materialfor use in a current DVD-R disc;

FIGS. 5A and 5B are exemplary views each showing comparison of shapes ofrecording films formed in a pre-pit area or a pre-groove area 10 in thephase shift recording film and the organic dye recording film;

FIGS. 6A and 6B are exemplary views each showing a specific plasticdeformation state of a transparent substrate 2-2 at a position of arecording mark 9 in a write-once type information storage medium using aconventional organic dye material;

FIGS. 7A, 7B and 7C are exemplary views relating to a shape ordimensions of a recording film in which a principle of recording iseasily established;

FIGS. 8A, 8B and 8C are exemplary views each showing a shape anddimensions of the recording film;

FIG. 9 is an exemplary view illustrating light absorption spectrumcharacteristics in an unrecorded state of a an “H-L” (high to low)recording film;

FIG. 10 is an exemplary view illustrating light absorption spectrumcharacteristics in a recording mark of the “H-L” recording film;

FIG. 11 is an exemplary view illustrating one embodiment of aninformation recording/reproducing apparatus according to the presentinvention;

FIG. 12 is an exemplary view showing a detailed structure of peripheralportions including a sync code position sampling section 145 shown inFIG. 11;

FIG. 13 is an exemplary view showing a signal processor circuit using aslice level detecting system;

FIG. 14 is an exemplary view showing a detailed internal structure of aslicer 310 shown in FIG. 13;

FIG. 15 is an exemplary view showing a signal processor circuit using aPRML detecting technique;

FIG. 16 is an exemplary view showing an internal structure of a Viterbidecoder 156 shown in FIG. 11 or FIG. 15;

FIG. 17 is an exemplary view showing a state transition in PR (1, 2, 2,2, 1) class;

FIG. 18 is an exemplary view showing a waveform (Write Strategy) of arecording pulse for carrying out test writing in a drive test zone;

FIG. 19 is an exemplary view showing a definition of a recording pulseshape;

FIGS. 20A, 20B and 20C are exemplary views of a recording pulse timingparameter setting table;

FIGS. 21A, 21B and 21C are exemplary views relating to values of eachparameter used when optimal recording power is checked;

FIG. 22 is an exemplary view showing a light reflectivity range of an“H-L” recording film and a “L-H” (low to high) recording film;

FIG. 23 is an exemplary view illustrating polarity of a detection signaldetected from the “H-L” recording film and the “L-H” recording film;

FIG. 24 is an exemplary view showing a comparison in light reflectionfactor between the “H-L” recording film and the “L-H” recording film;

FIG. 25 is an exemplary view showing light absorption spectrumcharacteristics in an unrecorded state of the “L-H” recording film;

FIG. 26 is an exemplary view showing a change of light absorptionspectrum characteristics in a recorded state and an unrecorded state ofthe “L-H” recording film;

FIG. 27 is an exemplary general structural formula of a cyanine dyeutilized for a cation portion of the “L-H” recording film;

FIG. 28 is an exemplary general structural formula of a styril dyeutilized for a cation portion of the “L-H” recording film;

FIG. 29 is an exemplary general structural formula of a monomethinecyanine dye utilized for a cation portion of the “L-H” recording film;

FIG. 30 is an exemplary general structural formula of a formazane metalcomplex utilized for an anion portion of the “L-H” recording film;

FIG. 31 is an exemplary view showing an example of an internal structureand dimensions of an information storage medium;

FIG. 32 is an exemplary view showing a value of a general parameter in aread-only type information storage medium;

FIG. 33 is an exemplary view showing a value of a general parameter in awrite-once type information storage medium;

FIG. 34 is an exemplary view showing a value of a general parameter in arewritable type information storage medium;

FIGS. 35A, 35B and 35C are exemplary views each comparing detailedinternal data structures of a system lead-in area SYLDI and a datalead-in area DTLDI in a variety of information storage mediums;

FIGS. 36A, 36B, 36C and 36D are exemplary views each showing an internaldata structure of an RMD duplication zone RDZ and a recording positionmanagement zone RMZ located in a write-once type information storagemedium;

FIGS. 37A, 37B, 37C, 37D, 37E and 37F are exemplary views each showing acomparison of internal data structures of a data area DTA and a datalead-out area DTLDO in the variety of information storage mediums;

FIGS. 38A, 38B and 38C are exemplary views each showing an internal datastructure of recording position management data RMD;

FIGS. 39A, 39B, 39C and 39D are exemplary views each showing anotherembodiment which is different from

FIGS. 40A, 40B, 40C and 40D are exemplary views each illustrating astructure of a border area in the write-once type information storagemedium;

FIGS. 41A, 41B, 41C and 41D are exemplary views each showing an internaldata structure of a control data zone CDZ and an R physical informationzone RIZ;

FIG. 42 is an exemplary view showing specific information contents inphysical format information PFI and R physical information formatinformation R_PFI;

FIG. 43 is an exemplary view showing a comparison of the contents ofdetailed information recorded in allocation place information on a dataarea DTA;

FIG. 44 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIG. 45 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIG. 46 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIG. 47 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIG. 48 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIG. 49 is an exemplary view showing a detailed data structure inrecording position management data RMD;

FIGS. 50A, 50B, 50C and 50D are exemplary views each showing an internaldata structure of a data ID;

FIG. 51 is an exemplary view adopted to explain another embodimentrelevant to a data structure in recording position management data RMD;

FIG. 52 is an exemplary view adopted to explain the other embodimentrelevant to a data structure in recording position management data RMD;

FIG. 53 is an exemplary view showing another data structure in an RMDfield 1;

FIG. 54 is an exemplary view of another embodiment relating to physicalformat information and R physical format information;

FIGS. 55A, 55B, and 55C are exemplary views illustrating anotherembodiment relating to an internal data structure of the control datazone;

FIG. 56 is an exemplary view showing an outline of converting proceduresfor configuring a physical sector structure;

FIG. 57 is an exemplary view showing an internal structure of a dataframe;

FIGS. 58A and 58B are exemplary views each showing an initial valueassigned to a shift register when producing a frame after scrambled anda circuit configuration of a feedback shift register;

FIG. 59 is an exemplary view illustrating an ECC block structure;

FIG. 60 is an exemplary view illustrating frame arrangement afterscrambled;

FIG. 61 is an exemplary view illustrating a PO interleaving method;

FIGS. 62A and 62B are exemplary views each illustrating an internalstructure of a physical sector;

FIG. 63 is an exemplary view of the contents of a sync code pattern;

FIG. 64 is an exemplary view showing a detailed structure of an ECCblock after PO-interleaved, shown in FIG. 61;

FIG. 65 is an exemplary view illustrating a reference code pattern;

FIGS. 66A, 66B, 66C, and 66D are exemplary views showing a comparison ofa data recording format by a variety of information storage mediums;

FIGS. 67A and 67B are exemplary views each illustrating a comparisonwith a conventional example of a data structure in the variety ofinformation storage mediums;

FIG. 68 is an exemplary view illustrating a comparison with aconventional example of a data structure in the variety of informationstorage mediums;

FIG. 69 is an exemplary view illustrating 180 degree phase modulationand an NRZ technique in wobble modulation;

FIG. 70 is an exemplary view illustrating a relationship between awobble shape and an address bit in an address bit area;

FIGS. 71A, 71B, 71C and 71D are exemplary views illustrating acomparison in positional relationship between a wobble sync pattern andan inside of a wobble data unit;

FIGS. 72A, 72B, 72C, and 72D are exemplary view relating to an internaldata structure of wobble address information in a write-once typeinformation storage medium;

FIG. 73 is an exemplary view illustrating a setting location of amodulation area on the write-once type information storage medium;

FIGS. 74A, 74B, 74C and 74D are exemplary views each illustrating asetting location of a modulation area in a physical segment on thewrite-once type information storage medium;

FIGS. 75A and 75B are exemplary view illustrating a layout in arecording cluster;

FIGS. 76A, 76B, 76C, 76D, 76E and 76F are exemplary views each showing adata recording method for recording rewritable data on a rewritable typeinformation storage medium;

FIG. 77 is an exemplary view illustrating a data random shift of therewritable data recorded on the rewritable type information storagemedium;

FIG. 78 is an exemplary view illustrating a method for writingwrite-once type data once, the data being recorded on the write-oncetype information storage medium;

FIG. 79 is an exemplary view illustrating a cause of an occurrence of acrosstalk in wobble signal;

FIG. 80 is an exemplary view showing a method for measuring a maximumvalue (Cwmax) and a minimum value (Cwmin) of a carrier level of a wobbledetection signal;

FIG. 81 is an exemplary flow chart illustrating a method for measuring amaximum amplitude (Wppmax) and a minimum amplitude (Wppmin) of thewobble detection signal;

FIGS. 82A and 82B are exemplary views each showing characteristics ofthe wobble signal and a track shift signal;

FIG. 83 is an exemplary flow chart illustrating a method for measuring a(I1-I2) pp signal;

FIG. 84 is an exemplary view illustrating a circuit for measuring NBSNRin response to a square waveform of the wobble signal;

FIG. 85 is an exemplary flow chart illustrating a method for measuringNBSNR in response to the square waveform of the wobble signal;

FIGS. 86A and 86B are exemplary views each illustrating characteristicsof a spectrum analyzer detection signal of the wobble signal caused byphase modulation;

FIG. 87 is an exemplary view illustrating the spectrum analyzer waveformof the phase modulated wobble signal;

FIG. 88 is an exemplary view illustrating the spectrum analyzer waveformproduced after squaring the wobble signal;

FIG. 89 is an exemplary view illustrating a method for measuring asuppression ratio in the present embodiment;

FIGS. 90A and 90B are exemplary views each illustrating anotherembodiment of a detection signal level conforming to an H format in an“H-L” recording film;

FIGS. 91A and 91B are exemplary views each illustrating anotherembodiment of the detection signal level conforming to the H format inan “L-H” recording film;

FIG. 92 is an exemplary view illustrating a relationship between adetection range and a detection signal level of a preamplifier 304;

FIGS. 93A and 93B are exemplary views each illustrating a method formaking a search for a lastly recorded location;

FIG. 94 is an exemplary flow chart for making a search for the lastlyrecorded location in an information recording/reproducing apparatus;

FIG. 95 is an exemplary flow chart for making a search for the lastlyrecorded location in an information reproducing apparatus;

FIGS. 96A, 96B and 96C are exemplary views each illustrating a settingstate of a recording position management zone RMZ in a bordered areaBRDA;

FIG. 97 is an exemplary view illustrating a method for setting therecording position management zone RMZ in the bordered area BRDA;

FIGS. 98A and 98B are exemplary views illustrating a data structure in astate in which reproduction can be carried out by the informationreproducing apparatus;

FIG. 99 is an exemplary view illustrating a border close processingmethod;

FIGS. 100A and 100B are exemplary views each illustrating anotherembodiment of a method for setting an extended drive test zone;

FIG. 101 is an exemplary view relating to a method for controllingpolarity of a portion 13T;

FIGS. 102A and 102B are exemplary views each illustrating a reproductionsignal from a burst cutting area;

FIG. 103 is an exemplary view illustrating a BCA data structure;

FIG. 104 is an exemplary view illustrating bit patterns of a BCA syncbyte SBBCA and a BCA re-sync RSBCA;

FIGS. 105A, 105B, 105C, 105D, 105E, 105F and 105G are exemplary viewseach illustrating an example of the contents of the BCA informationrecorded in the BCA data area;

FIGS. 106A, 106B, 106C, 106D and 106E are exemplary views eachillustrating a wobble address format in a write-once type informationstorage medium;

FIG. 107 is an exemplary view illustrating a relationship in physicalsegment setting location between the adjacent tracks;

FIGS. 108A and 108B are exemplary views each illustrating type selectionin setting location of a modulation area of an i+1-th adjacent track;

FIG. 109 is an exemplary view illustrating a setting location conditionin the case where a setting location type is selected as type 3;

FIG. 110 is an exemplary view illustrating a method for selecting asetting location type of the modulation area;

FIG. 111 is an exemplary flow chart illustrating an outline ofprocedures for recording information in a medium (such as HD DVD-R disc)including information contained in a recording management data field 1(RMD Field1) or the like;

FIG. 112 is an exemplary flow chart illustrating an outline ofprocedures for reproducing information from a medium (such as HD DVD-Rdisc) having recorded therein information contained in a reproductionmanagement data field 1 (RMD Field1) or the like;

FIG. 113 is an exemplary view illustrating a detail on informationstored in the recording management data field 1 (RMD Field1);

FIG. 114 is an exemplary view showing specific information contents inphysical format information PFI and R physical information formatinformation R_PFI;

FIG. 115 is an exemplary view showing a comparison of the contents ofdetailed information recorded in allocation place information on a dataarea DTA;

FIG. 116 is an exemplary view showing a detailed data structure inrecording position management data RND;

FIG. 117 shows an exemplary sectional view of a dual layer recordabledisc according to a second embodiment of the present invention;

FIGS. 118A and 118B show exemplary views explaining a space layerthickness measurement;

FIG. 119 shows an exemplary view showing the ray bundle on the otherlayer while reading and writing of a layer of the disc;

FIG. 120 shows an exemplary view showing the clearance to prevent theinfluence of the other layer at the worst case;

FIG. 121 shows an exemplary view showing the clearance in the number ofphysical sectors;

FIG. 122 shows an exemplary view showing a physical sector number onLayer 0 and the corresponding recordable physical sectors on Layer 1;

FIG. 123 shows an exemplary view showing the reference values for themeasurement;

FIG. 124 shows an exemplary view showing the general parameters;

FIG. 125 shows an exemplary view showing the schematic of lead-in areaand lead-out area;

FIG. 126 shows an exemplary view showing the schematic of originalmiddle area;

FIG. 127 shows an exemplary view showing the track path;

FIGS. 128A, 128B, and 128C show an exemplary view showing the example ofdata recording procedure (part 1);

FIGS. 129A, 129B, and 129C show an exemplary view showing the example ofdata recording procedure (part 2);

FIG. 130 shows an exemplary view showing the physical sector layout andnumbering;

FIG. 131 shows an exemplary view showing the layout of address field inWAP (Wobble Address in Periodic position);

FIG. 132 shows an exemplary view showing the primary WDU (Wobble DataUnit) in sync field;

FIG. 133 shows an exemplary view showing the primary WDU in addressfield;

FIG. 134 shows an exemplary view showing the secondary WDU in syncfield;

FIG. 135 shows an exemplary view showing the secondary WDU in addressfield;

FIG. 136 shows an exemplary view showing the WDU in unity field;

FIG. 137 shows an exemplary view showing the structure of the lead-inarea;

FIG. 138 shows an exemplary view showing the structure of a control datazone;

FIG. 139 shows an exemplary view showing a structure of a data segmentin a control data section;

FIG. 140 shows an exemplary view showing the physical formatinformation;

FIG. 141 shows an exemplary view showing the physical format information(part 1);

FIG. 142 shows an exemplary view showing the physical format information(part 2);

FIG. 143 shows an exemplary view showing the data area allocation;

FIG. 144 shows an exemplary view showing the layout of the RMD(Recording Management Data) duplication zone;

FIG. 145 shows an exemplary view showing the data structure of therecording management data;

FIG. 146 shows an exemplary view showing the RMD field 0;

FIG. 147 shows an exemplary view showing the data area allocation;

FIG. 148 shows an exemplary view showing the renewed data areaallocation;

FIG. 149 shows an exemplary view showing the drive test zone;

FIG. 150 shows an exemplary view showing the RMD field 1 (part 1);

FIG. 151 shows an exemplary view showing the RMD field 1 (part 2);

FIG. 152 shows an exemplary view showing the RMD field 4;

FIG. 153 shows an exemplary view showing the RMD field 5 to RMD field21;

FIG. 154 shows an exemplary view showing the structure of a physicalsector block in a R-physical format information zone;

FIG. 155 shows an exemplary view showing the physical formatinformation;

FIG. 156 shows an exemplary view showing the data area allocation;

FIGS. 157A and 157B shows an exemplary view showing the schematic ofmiddle area before/after the expansion;

FIG. 158 shows an exemplary view showing the structure of the middlearea before the expansion;

FIG. 159 shows an exemplary view showing the structure of the middlearea after the large size expansion;

FIG. 160 shows an exemplary view showing the number of physical sectorsin guard track zone;

FIG. 161 shows an exemplary view showing the structure of the lead-outarea;

FIGS. 162A and 162B show an exemplary views showing the example of thedata area structure for single RZone recording;

FIG. 163 shows an exemplary view showing the example of data areastructure for reserve RZone recording;

FIG. 164 shows an exemplary view showing the example of final areastructure for recording user data on Layer 1;

FIGS. 165A and 165B show an exemplary view showing the example of finalarea structure for not recording user data on Layer 1;

FIG. 166 shows an exemplary view showing the terminator location for notrecording user data on Layer 1;

FIG. 167 shows an exemplary view showing the channel bit lengthmeasurement;

FIGS. 168A and 168B shows an exemplary view showing the schematic of twoadjacent tracks;

FIGS. 169A and 169B show an exemplary view showing the type selectionfor track #i+1;

FIG. 170 shows an exemplary view showing the example of the case thattype 3 physical segment is selected;

FIG. 171 shows an exemplary view showing the adaptive write controltables; and

FIG. 172 shows an exemplary view showing the conditions for writing dataon Layer 1.

DETAILED DESCRIPTION

Various embodiments according to the invention will be describedhereinafter with reference to the accompanying drawings. In general,according to one embodiment of the invention, an information storagemedium comprises information layers of layer 0 and layer 1 which aresequentially arranged from a read surface, recording is carried out froman inner periphery to an outer periphery of layer 0, and recording iscarried out from an outer periphery to an inner periphery of layer 1,wherein the information layer of layer 0 comprises a system lead-inarea, a data lead-in area, a data area, and a middle area which arearranged from an inner periphery; the information layer of layer 1comprises a system lead-out area, a data lead-out area, a data area, anda middle area which are arranged from an inner periphery; an endposition of the data area of layer 1 is positioned at a periphery outerthan a start position of the data area of layer 0; the data lead-in areacomprises a guard track zone corresponding to a zone which is wider thana test zone in the data lead-out area; the data lead-out area comprisesa guard track zone corresponding to a zone which is wider than a testzone and a management zone in the data lead-in area; the middle area oflayer 0 comprises a guard track zone corresponding to a zone which iswider than a test zone in the middle area of layer 1; and the middlearea of layer 1 comprises a blank zone corresponding to a zone which iswider than a test zone in the middle area of layer 0.

Hereinafter, embodiments of a recording medium and a method forrecording and reproducing the recording medium according to theinvention will be described with reference to the accompanying drawings.

Summary of Characteristics and Advantageous Effect of the Invention

1) Relationship between track pitch/bit pitch and optimal recordingpower:

Conventionally, in the case of a principle of recording with a substrateshape change, if a track pitch is narrowed, a “cross-write” or a“cross-erase” occurs, and if bit pitches are narrowed, an inter-codecrosstalk occurs. As in the present embodiment, since a principle ofrecording without a substrate shape change is devised, it becomespossible to achieve high density by narrowing track pitches/bit pitches.In addition, at the same time, in the above described principle ofrecording, recording sensitivity is improved, enabling high speedrecording and multi-layering of a recording film because optimalrecording power can be lowly set.

2) In optical recording with a wavelength of 620 nm or less, an FCCblock is composed of a combination of a plurality of small ECC blocksand each item of data ID information in two sectors is disposed in asmall ECC block which is different from another:

According to the invention, as shown in FIG. 2B, a local opticalcharacteristic change in a recording layer 3-2 is a principle ofrecording, and thus, an arrival temperature in the recording layer 3-2at the time of recording is lower than that in the conventionalprinciple of recording due to plastic deformation of a transparentsubstrate 2-2 or due to thermal decomposition or gasification(evaporation) of an organic dye recording material. Therefore, adifference between an arrival temperature and a recording temperature ina recording layer 3-2 at the time of playback is small. In the presentembodiment, an interleaving process between small ECC blocks and data IDallocation are contrived in one ECC block, thereby improvingreproduction reliability in the case where a recording film is degradedat the time of repetitive playback.

3) Recording is carried out by light having a wavelength which isshorter than 620 nm, and a recorded portion has a higher reflectionfactor than a non-recording portion:

Under the influence of absorption spectrum characteristics of a generalorganic dye material, under the control of light having a wavelengthwhich is shorter than 620 nm, the light absorbance is significantlylowered, and recording density is lowered. Therefore, a very largeamount of exposure is required to generate a substrate deformation whichis a principle of recording in a conventional DVD-R. By employing an“Low to High (hereinafter, abbreviated to as L-H) organic dye recordingmaterial” whose reflection factor is increased more significantly thanthat of an unrecorded portion in a portion (recording mark) recorded asin the present embodiment, a substrate deformation is eliminated byforming a recording mark using a “discoloring action due to dissociationof electron coupling”, and recording sensitivity is improved.

4) “L-H” organic dye recording film and PSK/FSK modulation wobblegroove:

Wobble synchronization at the time of playback can be easily obtained,and reproduction reliability of a wobble address is improved.

5) “L-H” organic dye recording film and reproduction signal modulationdegree rule:

A high C/N ratio relating to a reproduction signal from a recording markcan be ensured, and reproduction reliability from the recording mark isimproved.

6) Light reflection factor range in “L-H” organic dye recording film andmirror section:

A high C/N ratio relating to a reproduction signal from a system lead-inarea SYLDI can be ensured and high reproduction reliability can beensured.

7) “L-H” organic dye recording film and light reflection factor rangefrom unrecorded area at the time of on-track:

A high C/N rate relating to a wobble detection signal in an unrecordedarea can be ensured, and high reproduction reliability relevant towobble address information can be ensured.

8) “L-H” organic dye recording film and wobble detection signalamplitude range:

A high C/N ratio relating to a wobble detection signal can be ensuredand high reproduction reliability relevant to wobble address informationcan be ensured.

<<Table of Contents>>

Chapter 0: Description of Relationship between Wavelength and thePresent Embodiment

Wavelength used in the present embodiment.

Chapter 1: Description of Combination of Constituent Elements ofInformation Storage Medium in the Present Embodiment:

FIG. 1 shows an illustration of the contents of constituent elements ofthe information storage medium in the present embodiment.

Chapter 2: Description of Difference in reproduction signal betweenPhase Change Recording Film and Organic Dye Recording Film

2-1) Difference in Principle of Recording/Recording Film and Differencein Basic Concept Relating to Generation of Reproduction Signal . . .Definition of λ_(max write) 2-2) Difference of Light Reflection LayerShape in Pre-pit/Pre-groove Area

Optical reflection layer shape (difference in spin coating andsputtering vapor deposition) and influence on a reproduction signal.

Chapter 3: Description of Characteristics of Organic Dye Recording Filmin the Present Embodiment

3-1) Problem(s) relevant to achievement of high density in write-oncetype recording film (DVD-R) using conventional organic dye material 3-2)Description of basic characteristics common to organic dye recordingfilms in the present embodiment:

Lower limit value of recording layer thickness, channel bit length/trackpitch in which advantageous effect is attained in the invention,repetitive playback enable count, optimal reproduction power,

Rate between groove width and land width . . . Relationship with wobbleaddress format

Relationship in recording layer thickness between groove section andland section

Technique of improving error correction capability of recordinginformation and combination with PRML

3-3) Recording characteristics common to organic dye recording films inthe present embodiment

Upper limit value of optimal recording power

3-4) Description of characteristics relating to a “High to Low(hereinafter, abbreviated to as H-L)” recording film in the presentembodiment:

Upper limit value of reflection factor in unrecorded layer

Relationship between a value of λ_(max write) and a value of λ1_(max)(absorbance maximum wavelength at unrecorded/recorded position)

Relative values of reflection factor and degree of modulation atunrecorded/recorded position and light absorption values at reproductionwavelength . . . n·k range

Relationship in upper limit value between required resolutioncharacteristics and recording layer thickness

Chapter 4: Description of Reproducing Apparatus or Recording/ReproducingApparatus and Recording Condition/Reproducing Circuit

4-1) Description of structure and characteristics of reproducingapparatus or recording/reproducing apparatus in the present embodiment:Use wavelength range, NA value, and RIM intensity 4-2) Description ofreproducing circuit in the present embodiment 4-3) Description ofrecording condition in the present embodiment

Chapter 5: Description of Specific Embodiments of Organic Dye RecordingFilm in the Present Embodiment

5-1) Description of characteristics relating to “L-H” recording film inthe present embodiment

Principle of recording and reflection factor and degree of modulation atunrecorded/recorded position

5-2) Characteristics of light absorption spectra relating to “L-H”recording film in the present embodiment:

Condition for setting maximum absorption wavelength λ_(max write), valueof Al₄₀₅ and a value of Ah₄₀₅

5-3) Anion portion: Azo metal complex+cation portion: Dye 5-4) Use of“copper” as azo metal complex+main metal:

Light absorption spectra after recorded are widening in an “H-L”recording film, and are narrowed in an “L-H” recording film.

Upper limit value of maximum absorption wavelength change amount beforeand after recording:

A maximum absorption wavelength change amount before and after recordingis small, and absorbance at a maximum absorption wavelength changes.

Chapter 6: Description Relating to Pre-Groove Shape/Pre-Pit Shape inCoating Type Organic Dye Recording Film and on Light Reflection LayerInterface

6-1) Light reflection layer (material and thickness):

Thickness range and passivation structure . . . Principle of recordingand countermeasures against degradation (Signal is degraded more easilythan substrate deformation or than cavity)

6-2) Description relating to pre-pit shape in coating type organic dyerecording film and on light reflection layer interface:

Advantageous effect achieved by widening track pitch/channel bit pitchin system lead-in area:

Reproduction signal amplitude value and resolution in system lead-inarea:

Rule on step amount at land portion and pre-pit portion in lightreflection layer 4-2:

6-3) Description relating to pre-groove shape in coating type organicdye recording film and on light reflection layer interface:

Rule on step amount at land portion and pre-groove portion in lightreflection layer 4-2:

Push-pull signal amplitude range:

Wobble signal amplitude range (combination with wobble modulationsystem)

Chapter 7: Description of First Next-Generation Optical Disc: HD DVDSystem (Hereinafter, Referred to as H Format):

Principle of recording and countermeasure against reproduction signaldegradation (Signal is degraded more easily than substrate deformationor than cavity):

Error Correction Code (ECC) structure, PRML (Partial Response MaximumLikelihood) System:

Relationship between a wide flat area in the groove and wobble addressformat.

In the write-once recording, overwriting is carried out in a VFO areawhich is non-data area.

Influence of DC component change in overwrite area is reduced. Inparticular, advantageous effect on “L-H” recording film is significant.

Now, a description of the present embodiment will be given here.

Chapter 0: Description of Relationship between Use Wavelength and thePresent Embodiment

As a write-once type optical disc obtained by using an organic dyematerial for a recording medium, there has been commercially available aCD-R disc using a recording/reproducing laser light source wavelength of780 nm and a DVD-R disc using a recording/reproducing laser light beamwavelength of 650 nm. Further, in a next-generation write-once typeinformation storage medium having achieved high density, it is proposedthat a laser light source wavelength for recording or reproducing, whichis close to 405 nm (namely, in the range of 355 nm to 455 nm), is usedin either of H format (D1) and B format (D2) of FIG. 1 described later.In a write-once type information storage medium using an organic dyematerial, recording/reproducing characteristics sensitively changes dueto a slight change of a light source wavelength. In principle, densityis increased in inverse proportion to a square of a laser light sourcewavelength for recording/reproducing, and thus, it is desirable that ashorter laser light source wavelength be used for recording/reproducing.However, for the above described reason, an organic dye materialutilized for a CD-R disc or a DVD-R disc cannot be used as a write-oncetype information storage medium for 405 nm. Moreover, because 405 nm isclose to an ultraviolet ray wavelength, there can easily occur adisadvantage that a recording material “which can be easily recordedwith a light beam of 405 nm”, is easily changed in characteristics dueto ultraviolet ray irradiation, lacking a long period stability.Characteristics are significantly different from each other depending onorganic dye materials to be used, and thus, it is difficult to determinethe characteristics of these dye materials in general. As an example,the foregoing characteristics will be described by way of a specificwavelength. With respect to an organic dye recording material optimizedwith a light beam of 650 nm in wavelength, the light to be used becomesshorter than 620 nm, recording/reproducing characteristics significantlychange. Therefore, in the case where a recording/reproducing operationis carried out with a light beam which is shorter than 620 nm inwavelength, there is a need for new development of an organic dyematerial which is optimal to a light source wavelength of recordinglight or reproducing light. An organic dye material of which recordingcan be easily carried out with a light beam shorter than 530 nm inwavelength easily causes characteristic degradation due to ultravioletray irradiation, lacking long period stability. In the presentembodiment, a description will be given with respect to an embodimentrelevant to an organic recording material suitable to use in close to405 nm. Namely, a description will be given with respect to anembodiment relating to an organic recording material which can be stablyused in the range of 355 nm to 455 nm in consideration of a fluctuationof a light emitting wavelength which depends on manufacturers ofsemiconductor laser light sources. That is, the scope of the presentembodiment corresponds to a light beam which is adapted to a lightsource of 620 nm in wavelength, and desirably, which is shorter than 530nm in wavelength (ranging from 355 nm to 455 nm in a definition in thenarrowest range).

In addition, the optical recording sensitivity due to light absorptionspectra of an organic dye material is also influenced by a recordingwavelength. An organic dye material suitable for long period stabilityis easily reduced in light absorbance relevant to a light beam which isshorter than 620 nm in wavelength. In particular, the light absorbanceis significantly lowered with respect to a light beam which is shorterthan 620 nm in wavelength, and in particular, is drastically reducedwith respect to a light beam which is shorter than 530 nm in wavelength.Therefore, in the case where recording is carried out with a laser lightbeam ranging from 355 nm to 455 nm in wavelength, which is the severestcondition, recording sensitivity is impaired because the lightabsorbance is low, and there is a need for a new design employing a newprinciple of recording as shown in the present embodiment.

The size of a focusing spot used for recording or reproducingapplication is reduced in proportion to a wavelength of a light beam tobe used. Therefore, from only a standpoint of the focusing spot size, inthe case where a wavelength is reduced to the above described value, anattempt is made to reduce a track pitch or channel bit length by awavelength component with respect to a current DVD-R disc (usewavelength: 650 nm) which is a conventional technique. However, asdescribed later in “3-2-A] Scope requiring application of techniqueaccording to the present embodiment”, as long as a principle ofrecording in a conventional write-once type information storage mediumsuch as a DVD-R disc is used, there is a problem that a track pitch or achannel bit length cannot be reduced. A track pitch or a channel bitlength can be reduced in proportion to the above described wavelength byutilizing a technique devised in the present embodiment described below.

Chapter 1: Description of Combination of Constituent Elements ofInformation Storage Medium in the Present Embodiment

In the present embodiment, there exists a great technical feature inthat an organic recording medium material (organic dye material) adaptedto a light source of 620 nm or less in wavelength has been devised. Suchan organic recording medium (organic dye material) has a uniquecharacteristic (Low to High characteristic) that a light reflectionfactor increases in a recording mark, which does not exist in aconventional CD-R disc or a DVD-R disc. Therefore, a technical featureof the present embodiment and a novel effect attained thereby occurs ina structure, dimensions, or format (information recording format)combination of the information storage medium which produces moreeffectively the characteristics of the organic recording material(organic dye materials) shown in the present embodiment. FIG. 1 shows acombination, which produces a new technical feature and advantageouseffect in the present embodiment. That is the information storage mediumin the present embodiment has the following constituent elements:

A] an organic dye recording film;

B] a pre-format (such as pre-groove shape/dimensions or pre-pitshape/dimensions);

C] a wobble condition (such as wobble modulation method and wobblechange shape, wobble amplitude, and wobble allocating method); and

D] a format (such as format for recording data which is to be recordedor which has been recorded in advance in information storage medium).

Specific embodiments of constituent elements correspond to the contentsdescribed in each column of FIG. 1. A technical feature and a uniqueadvantageous effect of the present embodiment occur in combination ofthe specific embodiments of the constituent elements shown in FIG. 1.Hereinafter, a description will be given with respect to a combinationstate of individual embodiments at a stage of explaining theembodiments. With respect to constituent elements, which do not specifya combination, it denotes that the following characteristics areemployed:

A5) an arbitrary coating recording film;

B3) an arbitrary groove shape and an arbitrary pit shape;

C4) an arbitrary modulation system;

C6) an arbitrary amplitude amount; and

D4) an arbitrary recording method and a format in a write-once medium.

Chapter 2: Description of Difference in Reproduction Signal BetweenPhase Change Recording Film and Organic Dye Recording Film 2-1)Difference in Principle of Recording/Recording Film and Difference inBasic Concept Relating to Generation of Reproduction Signal

FIG. 2A shows a standard phase change recording film structure (mainlyused for a rewritable-type information storage medium), and FIG. 2Bshows a standard organic dye recording film structure (mainly used for awrite-once type information storage medium). In the description of thepresent embodiment, a whole recording film structure excludingtransparent substrates 2-1 and 2-2 shown in FIGS. 2A and 2B (includinglight reflection layers 4-1 and 4-2) is defined as a “recording film”,and is discriminated from recording layers 3-1 and 3-2 in which arecording material is disposed. With respect to a recording materialusing a phase change, in general, an optical characteristic changeamount in a recorded area (in a recording mark) and an unrecorded area(out of a recording mark) is small, and thus, there is employed anenhancement structure for enhancing a relative change rate of areproduction signal. Therefore, in a phase change recording filmstructure, as shown in FIG. 2A, an undercoat intermediate layer 5 isdisposed between the transparent substrate 2-1 and a phase change typerecording layer 3-1, and an upper intermediate layer 6 is disposedbetween the light reflection layer 4-2 and the phase change typerecording layer 3-1. In the invention, as a material for the transparentsubstrates 2-1 and 2-2, there is employed a polycarbonate PC or anacrylic PMMA (poly methyl methacrylate) which is a transparent plasticmaterial. A center wavelength of a laser light beam 7 used in thepresent embodiment is 405 nm, and refractive index n₂₁, n₂₂ of thepolycarbonate PC at this wavelength is close to 1.62. Standardrefractive index n₃₁ and absorption coefficient k₃₁ in 405 nm at GeSbTe(germanium antimony tellurium) which is most generally used as a phasechange type recording material are n₃₁≅1.5 and k₃₁≅2.5 in a crystallinearea, whereas they are n₃₁≅2.5 and k₃₁≅1.8 in an amorphous area. Thus, arefractive index (in the amorphous area) of a phase change typerecording medium is different from a refractive index of the transparentsubstrate 2-1, and reflection of a laser light beam 7 on an interfacebetween the layers is easily occurred in a phase change recording filmstructure. As described above, for the reasons why (1) a phase changerecording film structure takes an enhancement structure; and (2) arefractive index difference between the layers is great or the like, alight reflection amount change at the time of reproduction from arecording mark recorded in a phase change recording film (a differentialvalue of a light reflection amount from a recording mark and a lightreflection amount from an unrecorded area) can be obtained as aninterference result of multiple reflection light beams generated on aninterface between the undercoat intermediate layer 5, the recordinglayer 3-1, the upper intermediate layer 6, and the light reflectionlayer 4-2. In FIG. 2A, although the laser light beam 7 is apparentlyreflected on an interface between the undercoat intermediate layer 5 andthe recording layer 3-1, an interface between the recording layer 3-1and the upper intermediate layer 6, and an interface between the upperintermediate layer 6 and the light reflection layer 4-2, in actuality, areflection light amount change is obtained as an interference resultbetween a plurality of multiple reflection light beams.

In contrast, an organic dye recording film structure takes a very simplelaminate structure made of an organic dye recording layer 3-2 and alight reflection layer 4-2. An information storage medium (optical disc)using this organic dye recording film is called a write-once typeinformation storage medium, which enables only one time of recording.However, unlike a rewritable-type information storage medium using thephase change recording medium, this medium cannot carry out an erasingprocess or a rewriting process of information which has been recordedonce. A refractive index at 405 nm of a general organic dye recordingmaterial is often close to n₃₂≅1.4 (n₃₂=1.4 to 1.9 in the refractiveindex range at 405 nm of a variety of organic dye recording materials)and an absorption coefficient is often close to k₃₂≅0.2 (k₃₂≅0.1 to 0.2in the absorption coefficient range at 405 nm of a variety of organicdye recording materials). Because a refractive index difference betweenthe organic dye recording material and the transparent substrate 2-2 issmall, there hardly occurs a light reflection amount on an interfacebetween the recording layer 3-2 and the transparent substrate 2-2.Therefore, an optical reproduction principle of an organic colorrecording film (reason why a reflection light amount change occurs) isnot “multiple interference” in a phase change recording film, and a mainfactor is a “light amount loss (including interference) midway of anoptical path with respect to the laser light beam 7 which comes backafter being reflected in the light reflection layer 4-2”. Specificreasons which cause a light amount loss midway of an optical pathinclude an “interference phenomenon due to a phase difference partiallycaused in the laser light 7” or an “optical absorption phenomenon in therecording layer 3-2”. The light reflection factor of the organic dyerecording film in an unrecorded area on a mirror surface on which apre-groove or a pre-pit does not exist is featured to be simply obtainedby a value obtained by subtracting an optical absorption amount when therecording layer 3-2 is passed from the light reflection factor of thelaser light beam 7 in the light reflection layer 4-2. As describedabove, this film is different from a phase change recording film whoselight reflection factor is obtained by calculation of “multipleinterference”.

First, a description will be given with respect to a principle ofrecording, which is used in a current DVD-R disc as a conventionaltechnique. In the current DVD-R disc, when a recording film isirradiated with the laser light beam 7, the recording layer 3-2 locallyabsorbs energy of the laser light beam 7, and becomes hot. If a specifictemperature is exceeded, the transparent substrate 2-2 is locallydeformed. Although a mechanism, which induces deformation of thetransparent substrate 2-2, is different depending on manufacturers ofDVD-R discs, it is said that this mechanism is caused by:

1) local plastic deformation of the transparent substrate 2-2 due togasification energy of the recording layer 3-2; and

2) transmission of a heat from the recording layer 3-2 to thetransparent substrate 2-2 and local plastic deformation of thetransparent substrate 2-2 due to the heat.

If the transparent substrate 2-2 is locally plastically deformed, therechanges an optical distance of the laser light beam 7 reflected in thelight reflection layer 4-2 through the transparent substrate 2-2, thelaser light beam 7 coming back through the transparent substrate 2-2again. A phase difference occurs between the laser light beam 7 from arecording mark, the laser light beam coming back through a portion ofthe locally plastically deformed transparent substrate 2-2, and a laserlight beam 7 from the periphery of the recording mark, the laser lightbeam coming back through a portion of a transparent substrate 2-2 whichis not deformed, and thus, a light amount change of reflection lightbeam occurs due to interference between these light beams. In addition,in particular, in the case where the above described mechanism of (1)has occurred, a change of a substantial refractive index n₃₂ produced bycavitations of the inside of the recording mark in the recording layer3-2 due to gasification (evaporation), or alternatively, a change of arefractive index n₃₂ produced due to thermal decomposition of an organicdye recording material in the recording mark, also contributes to theabove described occurrence of a phase difference. In the current DVD-Rdisc, until the transparent substrate 2-2 is locally deformed, there isa need for the recording layer 3-2 becoming hot (i.e., at a gasificationtemperature of the recording layer 3-2 in the above described mechanismof (1) or at an internal temperature of the recording layer 3-2 requiredfor plastically reforming the transparent substrate 2-2 in the mechanismof (2)) or there is a need for a part of the recording layer 3-2becoming hot in order to cause thermal decomposition or gasification(evaporation). In order to form a recording mark, there is a need forlarge amount of power of the laser light beam 7.

In order to form the recording mark, there is a necessity that therecording layer 3-2 can absorb energy of the laser light beam 7 at afirst stage. The light absorption spectra in the recording layer 3-2influence the recording sensitivity of an organic dye recording film. Aprinciple of light absorption in an organic dye recording material whichforms the recording layer 3-2 will be described with reference to (A3)of the present embodiment.

FIG. 3 shows a specific structural formula of the specific contents“(A3) azo metal complex+Cu” of the constituent elements of theinformation storage medium shown in FIG. 1. A circular periphery areaaround a center metal M of the azo metal complex shown in FIG. 3 isobtained as a light emitting area 8. When a laser light beam 7 passesthrough this light emitting area 8, local electrons in this lightemitting area 8 resonate to an electric field change of the laser lightbeam 7, and absorbs energy of the laser light beam 7. A value convertedto a wavelength of the laser light beam with respect to a frequency ofan electric field change at which these local electrons resonate mostand easily absorbs the energy is called a maximum absorption wavelength,and is represented by λ_(max). As a range of the light emitting area 8(resonation range) as shown in FIG. 3 increases, the maximum absorptionwavelength λ_(max) is shifted to the long wavelength side. In addition,in FIG. 3, the localization range of local electrons around the centermetal M (how large the center metal M can attract the local electrons tothe vicinity of the center) is changed by changing atoms of the centermetal M, and the value of the maximum absorption wavelength λ_(max)changes.

Although it can be predicted that the light absorption spectra of theorganic dye recording material in the case where there exists only onelight emitting area 8 which is absolute 0 degree at a temperature andhigh in purity draws narrow linear spectra in close to a maximumabsorption wavelength λ_(max), the light absorption spectra of a generalorganic recording material including impurities at a normal temperature,and further, including a plurality of light absorption areas exhibit awide light absorption characteristic with respect to a wavelength of alight beam around the maximum absorption wavelength λ_(max).

FIG. 4 shows an example of light absorption spectra of an organic dyerecording material used for a current DVD-R disc. In FIG. 4, awavelength of a light beam to be irradiated with respect to an organicdye recording film formed by coating an organic dye recording materialis taken on a horizontal axis, and absorbance obtained when an organicdye recording film is irradiated with a light beam having a respectivewavelength is taken on a vertical axis. The absorbance used here is avalue obtained by entering a laser light beam having incident intensityIo from the side of the transparent substrate 2-2 with respect to astate in which a write-once type information storage medium has beencompleted (or alternatively, a state in which the recording layer 3-2has been merely formed on the transparent substrate 2-2 (a state thatprecedes forming of the optical reflection layer 4-2 with respect to astructure of FIG. 2B)), and then, measuring reflected laser lightintensity Ir (light intensity It of the laser light beam transmittedfrom the side of the recording layer 3-2). The absorbance Ar (At) isrepresented by:Ar=−log₁₀(Ir/Io)   (A-1)Ar=−log₁₀(It/Io)   (A-2)

Unless otherwise specified, although a description will be givenassuming that the absorbance denotes absorbance Ar of a reflection shapeexpressed by formula (A-1), it is possible to define absorbance At of atransmission shape expressed by formula (A-2) without being limitedthereto in the present embodiment. In the embodiment shown in FIG. 4,there exist a plurality of light absorption areas, each of whichincludes the light emitting area 8, and thus, there exist a plurality ofpositions at which the absorbance becomes maximal. In this case, thereexist a plurality of maximum absorption wavelength λ_(max) when theabsorbance takes a maximum value. A wavelength of the recording laserlight in the current DVD-R disc is set to 650 nm. In the case wherethere exist a plurality of the maximum absorption wavelengths λ_(max) inthe present embodiment, a value of the maximum absorption wavelengthλ_(max) which is the closest to the wavelength of the recording laserlight beam becomes important. Therefore, only in the description of thepresent embodiment, the value of the maximum absorption wavelengthλ_(max) set at a position which is the closest to the wavelength of therecording laser light beam is defined as “λ_(max) write”; and isdiscriminated from another λ_(max) (λ_(max 0))

2-2) Difference of Light Reflection Layer Shape in Pre-Pit/Pre-GrooveArea

FIGS. 5A and 5B each show a comparison in shape when a recording film isformed in a pre-pit area or a pre-groove area 10. FIG. 5A shows a shaperelevant to a phase change recording film. In the case of forming any ofthe undercoat intermediate layer 5, the recording layer 3-1, the upperintermediate layer 6, and the light reflection layer 4-1 as well, any ofmethods of sputtering vapor deposition, vacuum vapor deposition, or ionplating is used in vacuum. As a result, in all of the layers,irregularities of the transparent substrate 2-1 are duplicatedcomparatively faithfully. For example, in the case where a sectionalshape in the pre-pit area or pre-groove area 10 of the transparentsubstrate 2-1 is rectangular or trapezoidal, the sectional shape of therecording layer 3-1 and the light reflection layer 4-1 each is alsorectangular or trapezoidal.

FIG. 5B shows a general recording film sectional shape of a currentDVD-R disc which is a conventional technique as a recording film in thecase where an organic dye recording film has been used. In this case, asa method for forming the recording film 3-2, there is used a methodcalled spin coating (or spinner coating) which is completely differentfrom that shown in FIG. 5A. The spin coating used here denotes a methodfor dissolving in an organic solvent an organic dye recording materialwhich forms the recording layer 3-2; applying a coating onto thetransparent substrate 2-2; followed by rotating the transparentsubstrate 2-2 at a high speed to spread a coating agent to the outerperiphery side of the transparent substrate 2-2 by a centrifugal force;and gasifying the organic solvent, thereby forming the recording layer3-2. Using this method, a process for coating the organic solvent isused, and thus, a surface of the recording layer 3-2 (an interface withthe light reflection layer 2-2) is easily flattened. As a result, thesectional shape on the interface between the light reflection layer 2-2and the recording layer 3-2 is obtained as a shape which is differentfrom the shape of the surface of the transparent substrate 2-2 (aninterface between the transparent substrate 2-2 and the recording layer3-2). For example, in a pre-groove area in which the sectional shape ofthe surface of the transparent substrate 2-2 (an interface between thetransparent substrate 2-2 and the recording layer 3-2) is rectangular ortrapezoidal, the sectional shape on the interface between the lightreflection layer 2-2 and the recording layer 3-2 is formed in asubstantially V-shaped groove shape. In a pre-pit area, the abovesectional shape is formed in a substantially conical side surface shape.Further, at the time of spin coating, an organic solvent is easilycollected at a recessed portion, and thus, the thickness Dg of therecording layer 3-2 in the pre-pit area or pre-groove area 10 (i.e., adistance from a bottom surface of the pre-pit area or pre-groove area toa position at which an interface relevant to the light reflection layer2-2 becomes the lowest) is larger than the thickness Dl in a land area12 (Dg>Dl). As a result, an amount of irregularities on an interfacebetween the transparent substrate 2-2 and the recording area 3-2 in thepre-pit area or pre-groove area 10 becomes substantially smaller than anamount of irregularities on the transparent substrate 2-2 and therecording layer 3-2.

As described above, the shape of irregularities on the interface betweenthe light reflection layer 2-2 and the recording layer 3-2 becomes bluntand an amount of irregularities becomes significantly small. Thus, inthe case where the shape and dimensions of irregularities on a surfaceof the transparent substrate 2 (pre-pit area or pre-groove area 10) areequal to each other depending on a difference in method for forming arecording film, the diffraction intensity of the reflection light beamfrom the organic dye recording film at the time of laser lightirradiation is degraded more significantly than the diffractionintensity of the reflection light beam from the phase change recordingfilm. As a result, in the case where the shape and dimensions ofirregularities on the surface of the transparent substrate 2 (pre-pitarea or pre-groove area 10) are equal to each other, as compared withuse of the phase change recording film, use of the conventional organicdye recording film is disadvantageously featured in that:

-   -   1) a degree of modulation of a light reproduction signal from        the pre-pit area is small, and signal reproduction reliability        from the pre-pit area is poor;    -   2) a sufficiently large track shift detecting signal is hardly        obtained in accordance with a push-pull technique from the        pre-groove area; and    -   3) a sufficient large wobble detecting signal is hardly obtained        in the case where wobbling occurs in the pre-groove area.

In addition, in a DVD-R disc, specific information such as addressinformation is recorded in a small irregular (pit) shape in a land area,and thus, a width Wl of the land area 12 is larger than a width Wg ofthe pre-pit area or pre-groove area 10 (Wg>Wl).

Chapter 3: Description of Characteristics of Organic Dye Recording Filmin the Present Embodiment 3-1) Problem(s) Relevant to Achievement ofHigh Density in Write-Once Type Recording Film (DVD-R) UsingConventional Organic Dye Material

As has been described in “2-1) Difference in recordingprinciple/recording film structure and difference in basic conceptrelating to generation of reproducing signal”, a general principle ofrecording of a current DVD-R and CD-R, which is a write-once typeinformation storage medium using a conventional organic dye materialincludes “local plastic deformation of transparent substrate 2-2” or“local thermal decomposition or “gasification” in recording layer 3-2”.FIGS. 6A and 6B each show a plastic deformation state of a specifictransparent substrate 2-2 at a position of a recording mark 9 in awrite-once type information storage medium using a conventional organicdye material. There exist two types of typical plastic deformationstates. There are two cases, i.e., a case in which, as shown in FIG. 6A,a depth of a bottom surface 14 of a pre-groove area at the position ofthe recording mark 9 (an amount of step relevant to an adjacent landarea 12) is different from a depth of a bottom surface of a pre-groovearea 11 in an unrecorded area (in the example shown in FIG. 6A, thedepth of the bottom surface 14 in the pre-groove area at the position ofthe recording mark 9 is shallower than that in the unrecorded area); anda case in which, as shown in FIG. 6B, a bottom surface 14 in apre-groove area at the position of the recording mark 9 is distorted andis slightly curved (the flatness of the bottom surface 14 is distorted:In the example shown in FIG. 6B, the bottom surface 14 in the pre-groovearea at the position of the recording mark 9 is slightly curved towardthe lower side). Both of these cases are featured in that a plasticdeformation range of the transparent substrate 2-2 at the position ofthe recording mark 9 covers a wide range. In the current DVD-R discwhich is a conventional technique, a track pitch is 0.74 μm, and achannel bit length is 0.133 μm. In the case of a large value of thisdegree, even if the plastic deformation range of the transparentsubstrate 2-2 at the position of the recording mark 9 covers a widerange, comparatively stable recording and reproducing processes can becarried out.

However, if the track pitch is narrower than 0.74 μm described above,the plastic deformation range of the transparent substrate 2-2 at theposition of the recording mark 9 covers a wide range, and thus, theadjacent tracks are adversely affected, and the recording mark 9 of theexisting adjacent track is substantially erased (cannot be reproduced)due to a “cross-write” or overwrite in which the recording mark 9 widensto the adjacent tracks. In addition, in a direction (circumferentialdirection) along the tracks, if the channel bit length is narrower than0.133 μm, there occurs a problem that inter-code interference appears;an error rate at the time of reproduction significantly increases; andthe reliability of reproduction is lowered.

3-2) Description of Basic Characteristics Common to Organic DyeRecording Film in the Present Embodiment 3-2-A] Range RequiringApplication of Technique According to the Present Embodiment

As shown in FIGS. 6A and 6B, in a conventional write-once typeinformation storage medium including plastic deformation of thetransparent substrate 2-2 or local thermal decomposition or gasificationphenomenon in the recording film 3-2, a description will be given belowwith respect to what degree of track pitch is narrowed when an adverseaffect appears or what degree of channel pit length is narrowed when anadverse effect appears and a result obtained after technical discussionhas been carried out with respect to a reason for such an adverseeffect. A range in which an adverse effect starts appearing in the caseof utilizing the conventional principle of recording indicates a range(suitable for the achievement of high density) in which advantageouseffect is attained due to a novel principle of recording shown in thepresent embodiment.

1) Condition of Thickness Dg of Recording Layer 3-2

When an attempt is made to carry out thermal analysis in order totheoretically identify a lower limit value of an allowable channel bitlength or a lower limit value of allowable track pitch, a range of thethickness Dg of a recording layer 3-2 which can be substantiallythermally analyzed becomes important. In a conventional write-once typeinformation storage medium (CD-R or DVD-R) including plastic deformationof the transparent substrate 2-2 as shown in FIGS. 6A and 6B, withrespect to a change of light reflection amount in the case where aninformation reproduction focusing spot is provided in the recording mark8 and in the case where the spot is in an unrecorded area of therecording layer 3-2, the largest factor is “an interference effect dueto a difference in optical distance in the recording mark 9 and inunrecorded area”. In addition, a difference in its optical difference ismainly caused by “a change of the thickness Dg of a physical recordinglayer 3-2 due to plastic deformation of the transparent substrate 2-2 (aphysical distance from an interface between the transparent substrate2-2 and the recording layer 3-2 to an interface between the recordinglayer 3-2 and a light reflection layer 4-2) and “a change of refractiveindex n₃₂ of the recording layer 3-2 in the recording mark 9”.Therefore, in order to obtain a sufficient reproduction signal (changeof light reflection amount) between the recording mark 9 and theunrecorded area, when a wavelength in vacuum of laser light beam isdefined as λ, it is necessary for the value of the thickness 3-2 in theunrecorded area has a size to some extent as compared with λ/n₃₂. Ifnot, a difference (phase difference) in optical distance between therecording mark 9 and the unrecorded area does not appear, and lightinterference effect becomes small. In reality, a minimum condition:Dg≧λ/8n ₃₂   (1)must be met, and desirably, a condition that:Dg≧λ/4n ₃₂   (2)must be met.

At a time point of current discussion, the vicinity of λ=405 nm isassumed. A value of refractive index n₃₂ of an organic dye recordingmaterial at 405 nm ranges from 1.3 to 2.0. Therefore, as a result ofsubstituting n₃₂=2.0 in formula (1), it is conditionally mandatory thata value of the thickness Dg of the recording layer 3-2 is:Dg≧25 nm   (3)

Here, discussion is made with respect to a condition when an organic dyerecording layer of a conventional write-once type information storagemedium (CD-R or DVD-R) including plastic deformation of the transparentsubstrate 2-2 has been associated with a light beam of 405 nm. Asdescribed later, in the present embodiment, although a description isgiven with respect to a case in which plastic deformation of thetransparent substrate 2-2 does not occur and a change of an absorptioncoefficient k₃₂ is a main factor of a principle of recording, it isnecessary to carry out track shift detection by using a DPD(Differential Phase Detection) technique from the recording mark 9, andthus, in reality, the change of the refractive index n₃₂ is caused inthe recording mark 9. Therefore, the condition for formula (3) becomes acondition, which should be met, in the present embodiment in whichplastic deformation of the transparent substrate 2-2 does not occur.

From another point of view as well, the range of the thickness Dg can bespecified. In the case of a phase change recording film shown in FIG.SA, when a refractive index of the transparent substrate is n₂₁, a stepamount between a pre-pit area and a land area is λ/(8n₂₁) when thelargest track shift detection signal is obtained by using a push-pulltechnique. However, in the case of an organic dye recording film shownin FIG. 5B, as described previously, the shape on an interface betweenthe recording layer 3-2 and the light reflection layer 4-2 becomesblunt, and a step amount becomes small. Thus, it is necessary toincrease a step amount between a pre-pit area and a land area on thetransparent substrate 2-2 more significantly than λ/(8n₂₂). For example,the refractive index at 405 nm in the case where polycarbonate has beenused as a material for the transparent substrate 2-2 is n₂₂≅1.62, andthus, it is necessary to increase a step amount between the pre-pit areaand the land area more significantly than 31 nm. In the case of using aspin coating technique, if the thickness Dg of the recording layer 3-2in the pre-groove area is greater than a step amount between the pre-pitarea and the land area on the transparent substrate 2-2, there is adanger that thickness Dl of the recording layer 3-2 in a land area 12 iseliminated. Therefore, from the above described discussion result, it isnecessary to meet a condition that:Dg>31 nm   (4)

The condition for formula (4) is also a condition, which should be metin the present embodiment in which plastic deformation of thetransparent substrate 2-2 does not occur. Although conditions for thelower limit values have been shown in formulas (3) and (4), the valueDg≅60 nm obtained by substituting n₃₂=1.8 for an equal sign portion informula (2) has been utilized as the thickness Dg of the recording layer3-2 used for thermal analysis.

Then, assuming polycarbonate used as a standard material of thetransparent substrate 2-2, 150° C. which is a glass transitiontemperature of polycarbonate has been set as an estimate value of athermal deformation temperature at the side of the transparent substrate2-2. For discussion using thermal analysis, a value of k₃₂=0.1 to 0.2has been assumed as a value of an absorption coefficient of the organicdye recording film 3-2 at 405 nm. Further, discussion has been made withrespect to a case in which an NA value of a focusing objective lens andan incident light intensity distribution when an objective lens ispassed is NA=60 and H format ((D1):NA=0.65 in FIG. 1) and B format((D2):NA=0.85 in FIG. 1) which is assumed condition in a conventionalDVD-R format.

2) Condition for Lower Limit Value of Channel Bit Length

A check has been made for a lengthwise change in a direction along atrack of an area reaching a thermal deformation temperature at the sideof a transparent substrate 2-2 which comes into contact with a recordinglayer 3-2 when recording power has been changed. Discussion has beenmade with respect to a lower limit value of an allowable channel bitlength considering a window margin at the time of reproduction. As aresult, if the channel bit length is slightly lower than 105 nm, it isconsidered that a lengthwise change in a direction along a track in anarea which reaches the thermal deformation temperature at the side ofthe transparent substrate 2-2 occurs according to the slight change ofrecording power, and a sufficient window margin cannot be obtained. Ondiscussion of thermal analysis, an analogous tendency is shown in thecase where the NA value is any one of 0.60, 0.65, and 0.85. Although afocusing spot size is changed by changing the NA value, a possibilitycause is believed to be that a thermal spreading range is wide (agradient of a temperature distribution at the side of the transparentsubstrate 2-2 which comes into contact with the recording layer 3-2) iscomparatively gentle). In the above thermal analysis, the temperaturedistribution at the side of the transparent substrate 2-2 which comesinto contact with the recording layer 3-2 is discussed, and thus, aneffect of the thickness Dg of the recording layer 3-2 does not appear.

Further, in the case where a shape change of the transparent substrate3-3 shown in FIGS. 6A and 6B occurs, a boundary position of a substratedeformation area blurs (is ambiguous), and thus, a window margin islowered more significantly. When a sectional shape of an area in whichthe recording mark 9 is formed is observed by an electron microscope, itis believed that a blurring amount of the boundary position of thesubstrate deformation area increases as the value of the thickness Dg ofthe recording layer 3-2 increases. With respect to the effect of thethermal deformation area length due to the above recording power change,in consideration of the blurring of the boundary position of thissubstrate deformation area, it is considered necessary that the lowerlimit value of the channel bit length allowed for allocation of asufficient window margin is in order of two times of the thickness Dg ofthe recording layer 3-2, and it is desirable that the lower limit valueis greater than 120 nm.

In the foregoing, a description has been principally given with respectto discussion using thermal analysis in the case where thermaldeformation of the transparent substrate 2-2 occurs. There also exists acase in which plastic deformation of the transparent substrate 2-2 isvery small as another principle of recording (mechanism of forming therecording mark 9) in a conventional write-once type information storagemedium (CD-R or DVD-R) and thermal deformation or gasification(evaporation) of the organic dye recording material in the recordinglayer 3-2 mainly occurs. Thus, an additional description will be givenwith respect to such a case. Although the gasification (evaporation)temperature of the organic dye recording material is different dependingon the type of the organic dye material, in general, the temperatureranges 220° C. to 37⁰° C., and a thermal decomposition temperature islower than this range. Although a glass transition temperature 150° C.of a polycarbonate resin has been presumed as an arrival temperature atthe time of substrate deformation in the above discussion, a temperaturedifference between 150° C. and 220° C. is small, and, when thetransparent substrate 2-2 reaches 150° C., the inside of the recordinglayer 3-2 exceeds 220° C. Therefore, although there exists an exceptiondepending on the type of the organic recording material, even in thecase where plastic deformation of the transparent substrate 2-2 is verysmall and thermal decomposition or gasification (evaporation) of theorganic dye recording material in the recording layer mainly occurs,there is obtained a result which is substantially identical to the abovediscussion result.

When the discussion result relating to the above channel bit length issummarized, in the conventional write-once type information storagemedium (CD-R or DVD-R) including plastic deformation of the transparentsubstrate 2-2, it is considered that, when a channel bit length isnarrower than 120 nm, the lowering of a window margin occurs, andfurther, if the length is smaller than 105 nm, stable reproductionbecomes difficult. That is, when the channel bit is smaller than 120 nm(105 nm), advantageous effect is attained by using a novel principle ofrecording shown in the present embodiment.

3) Condition for Lower Limit Value of Track Pitches

When a recording layer 3-2 is exposed at recording power, energy isabsorbed in the recording layer 3-2, and a high temperature is obtained.In a conventional write-once type information storage medium (CD-R orDVD-R), it is necessary to absorb energy in the recording layer 3-2until the transparent substrate 3-2 has reached a thermal deformationtemperature. A temperature at which a structural change of the organicdye recording material occurs in the recording layer 3-2 and a value ofa refractive index n₃₂ or an absorption coefficient k₃₂ starts itschange is much lower than an arrival temperature for the transparentsubstrate 2-2 to start thermal deformation. Therefore, the value of therefractive index n₃₂ or absorption coefficient k₃₂ changes in acomparatively wide range in the recording layer 3-2 at the periphery ofa recording mark 9, which is thermal deformed at the side of thetransparent substrate 2-2, and this change seems to cause “cross-write”or “cross-erase” for the adjacent tracks. It is possible to set a lowerlimit value of track pitch in which “cross-write” or “cross-erase” doesnot occur with the width of an area which reaches a temperature whichchanges the refractive index n₃₂ or absorption coefficient k₃₂ in therecording layer 3-2 when the transparent substrate 2-2 exceeds a thermaldeformation temperature. From the above point of view, it is consideredthat “cross-write” or “cross-erase” occurs in location in which thetrack pitch is equal to or smaller than 500 nm. Further, inconsideration of an effect of warping or inclination of an informationstorage medium or a change of recording power (recording power margin),it can be concluded difficult to set the track pitch to 600 nm or lessin the conventional write-once type information storage medium (CD-R orDVD-R) in which energy is absorbed in the recording layer 3-2 until thetransparent substrate 2-2 has reached a thermal deformation temperature.

As described above, even if the NA value is changed from 0.60, 0.65, andthen, to 0.85, substantially similar tendency is shown because thegradient of the temperature distribution in the peripheral recordinglayer 3-2 when the transparent substrate 2-2 has reached a thermaldeformation temperature at a center part is comparatively gentle, andthe thermal spread range is wide. In the case where plastic deformationof the transparent substrate 2-2 is very small and thermal decompositionor gasification (evaporation) of the organic dye recording material inthe recording layer 3-2 mainly occurs as another principle of recording(mechanism of forming the recording mark 9) in the conventionalwrite-once type information storage medium (CD-R or DVD-R), as has beendescribed in the section “(2) Condition for lower limit value of channelbit”, the value of track pitch at which “cross-write” or “cross-erase”starts is obtained as a substantially analogous result. For the abovedescribed reason, advantageous effect is attained by using a novelprinciple of recording shown in the present embodiment when the trackpitch Ls set to 600 nm (500 nm) or lower.

3-2-B] Basic Characteristics Common to Organic Dye Recording Material inthe Invention

As described above, in the case where plastic deformation of thetransparent substrate 2-2 is very small and thermal decomposition orgasification (evaporation) of the organic dye recording material in therecording layer 3-2 mainly occurs as another principle of recording(mechanism of forming the recording mark 9) in the conventionalwrite-once type information storage medium (CD-R or DVD-R), there occursa problem that a channel bit length or track pitches cannot be narrowedbecause the inside of the recording layer 3-2 or a surface of thetransparent substrate 2-2 reaches a high temperature at the time offorming the recording mark 9. In order to solve the above describedproblem, the present embodiment is featured in “inventive organic dyematerial” in which “a local optical characteristic change in therecording layer 3-2, which occurs at a comparatively low temperature, isa principle of recording” and “setting environment (recording filmstructure or shape) in which the above principle of recording easilyoccurs without causing a substrate deformation and gasification(evaporation) in the recording layer 3-2. Specific characteristics ofthe present embodiment can be listed below.

α] Optical Characteristic Changing Method Inside of Recording Layer 3-2

Chromogenic Characteristic Change

Change of light absorption sectional area due to qualitative change oflight emitting area 8 (FIG. 3) or change of molar molecule lightabsorption coefficient

The light emitting area 8 is partially destroyed or the size of thelight emitting area 8 changes, whereby a substantial light absorptionsectional area changes. In this manner, an amplitude (absorbance) at aposition of λ_(max write) changes in the recording mark 9 while aprofile (characteristics) of light absorption spectra (FIG. 4) itself ismaintained.

Change of Electronic Structure (Electron Orbit) Relevant to Electronswhich Contribute to a Chromogenic Phenomenon

Change of light absorption spectra (FIG. 4) based on discoloring actiondue to cutting of local electron orbit (dissociation of local molecularbonding) or change of dimensions or structure of light emitting area 8(FIG. 3)

Intra-Molecular (Inter-Molecular) Change of Orientation or Array

Optical characteristic change based on orientation change in azo metalcomplex shown in FIG. 3, for example

Molecular Structure Change in Molecule

For example, discussion is made with respect to an organic dye materialwhich causes either of dissociation between anion portion and cationportion, thermal decomposition of either of anion portion and cationportion, and a tar phenomenon that a molecular structure itself isdestroyed, and carbon atoms are precipitated (denaturing to black coaltar). As a result, the refractive index n₃₂ or absorption coefficientk₃₂ in the recording mark 9 is changed with respect to an unrecordedarea, enabling optical reproduction.

β] Setting Recording Film Structure or Shape, Making it Easy to StablyCause an Optical Characteristic Change of [a] Above:

The specific contents relating to this technique will be described indetail in the section “3-2-C] Ideal recording film structure which makesit easy to cause a principle of recording shown in the presentembodiment” and subsequent.

γ] Recording Power is Reduced in Order to Form Recording Mark in a Statein which Inside of Recording Layer or Transparent Substrate Surface isComparatively Low at Temperature

The optical characteristic change shown in [α] above occurs at atemperature lower than a deformation temperature of the transparentsubstrate 2-2 or a gasification (evaporation) temperature in therecording layer 3-2. Thus, the exposure amount (recording power) at thetime of recording is reduced to prevent the deformation temperature frombeing exceeded on the surface of the transparent substrate 2-2 or thegasification (evaporation) temperature from being exceeded in therecording layer 3-2. The contents will be described later in detail inthe section “3-3) Recording characteristics common to organic dyerecording layer in the present embodiment”. In addition, in contrast, itbecomes possible to determine whether or not the optical characteristicchange shown in [α] above occurs by checking a value of the optimalpower at the time of recording.

δ] Electron Structure in a Light Emitting Area is Stabilized, andStructural Decomposition Relevant to Ultraviolet Ray or ReproductionLight Irradiation is Hardly Generated

When ultraviolet ray is irradiated to the recording layer 3-2 orreproduction light is irradiated to the recording layer 3-2 at the timeof reproduction, a temperature size in the recording layer 3-2 occurs.There is a request for a seemingly contradictory performance thatcharacteristic degradation relevant to such a temperature rise isprevented and recording is carried out at a temperature lower than asubstrate deformation temperature or a gasification (evaporation)temperature in the recording layer 3-2. In the present embodiment, theabove described seemingly contradictory performance is ensured by“stabilizing an electron structure in a light emitting area”. Thespecific technical contents will be described in “Chapter 4 SpecificDescription of Embodiments of Organic Dye Recording Film in the PresentEmbodiment”.

ε] Reliability of Reproduction Information is Improved for a Case inwhich Reproduction Signal Degradation Due to Ultraviolet Ray orReproduction Light Irradiation Occurs

In the present embodiment, although a technical contrivance is made for“stabilizing an electron structure in a light emitting area”, thereliability of the recording mark 9 formed in a principle of recordingshown in the present embodiment may be principally lowered as comparedwith a local cavity in the recording layer 3-2 generated due to plasticdeformation or gasification (evaporation) of the surface of thetransparent substrate 2-2. As countermeasures against it, in the presentembodiment, advantageous effect that the high density and thereliability of recording information are achieved at the same time incombination with strong error correction capability (novel ECC blockstructure), as described later in “Chapter 7: Description of H Format”and “Chapter 8: Description of B Format”. Further, in the presentembodiment, PRML (Partial Response Maximum Likelihood) technique isemployed as a reproduction method, as described in the section “4-2Description of reproducing circuit in the present embodiment”, the highdensity and the reliability of recording information are achieved at thesame time in combination with an error correction technique at the timeof ML demodulation.

Among the specific characteristics of the above described presentembodiment, a description has been given with respect to the fact thatitems [α] to [γ] are the contents of technical contrivance newly devisedin the present embodiment in order to achieve “narrow track pitch” and“narrow channel bit length”. In addition, “narrow channel bit length”causes the achievement of “reduction of minimum recording mark length”.The meanings (objects) of the present embodiment relating to theremaining items [δ] and [ε] will be described in detail. At the time ofreproduction in the H format in the present embodiment, a passage speed(line speed) of a focusing spot of light passing through the recordinglayer 3-2 is set to 6.61 m/s, and the line speed in the B format is setin the range of 5.0 m/s to 10.2 m/s.

In any case, the line speed at the time of reproduction in the presentembodiment is equal to or greater than 5 m/s. As shown in FIG. 31, astart position of a data lead-in area DTLDI in the H format is 47.6 mmin diameter. In view of the B format as well, user data is recorded inlocation equal to or greater than 45 mm in diameter. An inner peripheryof 45 mm in diameter is 0.141 m, and thus, the rotation frequency of aninformation storage medium when this position is reproduced at a linespeed of 5 m/s is obtained as 35.4 rotations/second. Video imageinformation such as TV program is provided as one of the methodsutilizing a write-once type information storing medium according to thepresent embodiment. For example, when a user presses “pause (temporarystop) button” at the reproduction of the user's recorded video image, areproduction focusing spot stays on a track of its paused position. Whenthe spot stops on the track of the paused position, the user can startreproduction at the paused position immediately after a “reproductionstart button” has been pressed. For example, after the user has presseda “pause (temporary stop) button”, in the case where a customer visitsthe user's home immediately after the user has gone to toilet, there isa case in which the pause button is left to have been pressed for onehour while the user meets the customer. The write-once type informationstorage medium makes 35.4×60×60≅130,000 rotations for one hour, and thefocusing spot traces on the same track during this period (130,000repetitive playbacks). If the recording layer 3-2 is degraded due torepetitive playback and video image information cannot be reproducedafter this period, the user coming back one hour later cannot see anyportion of video image, and thus, gets angry, and in the worst case,there is a danger that the problem may be taken to court. Therefore, aminimum condition that, if the recorded video image information is notdestroyed even if such a pausing is left for one hour or longer (even ifcontinuous playback in the same track occurs), no video image data isdestroyed, requires to guarantee that at least 100,000 repetitiveplayback occurs, no reproduction degradation occurs. There is a rarecase in which a user repeats one-hour pausing (repetitive playback) 10times with respect to the same location in a general use condition.Therefore, when it is guaranteed that the write-once type informationstorage medium according to the present embodiment desirably makes1,000,000 repetitive playbacks, no problem occurs with use by thegeneral user, and it is considered sufficient to set to about 1,000,000times the upper limit value of the repetitive playback count as long asthe recording layer 3-2 is not degraded. If the upper limit value of therepetitive playback count is set to a value which significantly exceeds1,000,000 times, there occurs inconvenience that “recording sensitivityis lowered” or “medium price increases”.

In the case where the upper limit value of the above repetitivereproduction count is guaranteed, a reproduction power value becomes animportant factor. In the present embodiment, recording power is definedin a range set in formulas (8) to (13). It is said that a semiconductorlaser beam is featured in that continuous light irradiation is notstable in a value equal to or smaller than 1/80 of the maximum usepower. Because the power, which is 1/80 of the maximum use power, is inlocation in which light irradiation is just started (mode initiation isstarted), mode hopping is likely to occur. Therefore, at this lightirradiation power, the light reflected in the light reflection layer 4-2of the information storage medium comes back to a semiconductor laserlight source, there occurs a “return light noise” featured in that thelight emission amount always changes. Accordingly, in the presentembodiment, the values of the reproduction power is set below around thevalue which is 1/80 of the value described at the right side of formula(12) or formula (13):[Optical reproduction power]>0.19×(0.65/NA)²×(V/6.6)   (B-1)[Optical reproduction power]>0.19×(0.65/NA)²×(V/6.6)^(1.2)   (B-2)

In addition, the value of the optimal reproduction power is restrictedby a dynamic range of a power monitoring optical detector. Although notshown in an information recording/reproducing unit 141 of FIG. 11, arecording/reproducing optical head exists. This optical headincorporates an optical detector which monitors a light emission amountof a semiconductor laser light source. In the present embodiment, inorder to improve light irradiation precision of the reproduction powerat the time of reproduction, this optical detector detects a lightemission amount and applies a feedback to an amount of a current to besupplied to the semiconductor laser light source at the time of lightirradiation. In order to lower a price of the optical head, it isnecessary to use a very inexpensive optical detector. A commerciallyavailable, inexpensive optical detector is often molded with a resin (anoptical detecting unit is surrounded).

As disclosed in “Chapter 0: Description of Relationship between UseWavelength and the Present Embodiment”, 530 nm or less (in particular,455 nm or less) is used as a light source wavelength in the presentembodiment. In the case of this wavelength area, a resin with which theoptical detecting unit is molded (mainly, epoxy resin) causes such adegradation that occurs when ultraviolet ray has been irradiated if thewavelength light is irradiated (such as dark yellow discoloring oroccurrence of cracks (fine white stripes)) and the optical detectioncharacteristics are impaired. In particular, in the case of thewrite-once type information storage medium shown in the presentembodiment, a mold resin degradation is likely to occur because thestorage medium has a pre-groove area 11 as shown in FIGS. 8A, 8B and 8C.As a focus blurring detection system of an optical head, in order toremove adverse effect due to the diffraction light from this pre-groovearea 11, there is most often employed a “knife-edge technique” ofallocating an optical detector at an image forming position relevant tothe information storage medium (image forming magnification M is inorder of 3 times to 10 times). When the optical detector is arranged atthe image forming position, high optical density is irradiated onto amold resin because light beams are focused on the optical detector, andresin degradation due to this light irradiation is likely to occur. Thismold resin characteristic degradation mainly occurs due to a photon mode(optical action), and however, it is possible to predict an upper limitvalue of an allowable irradiation amount in comparison with a lightemission amount in a thermal mode (thermal excitation). Assuming theworst case, let us assume an optical system in which an optical detectoris arranged at an image forming position as an optical head.

From the contents described in '(1) Condition for thickness Dg ofrecording layer 3-2” in “3-2-A] Range requiring application of techniqueaccording to the present embodiment”, when an optimal characteristicchange (thermal mode) occurs in the recording layer 3-2 at the time ofrecording in the present embodiment, it is considered that a temperaturetemporarily rises in the range of 80° C. to 150° C. in the recordinglayer 3-2. In view of a room temperature of about 15° C., a temperaturedifference ΔT_(write) ranges from 65° C. to 135° C. Pulse lightemissions occur at the time of recording, and continuous light emissionsoccur at the time of reproduction. At the time of reproduction, thetemperature rises in the recording layer 3-2 and a temperaturedifference ΔT_(read) occurs. When an image forming magnification of adetecting system in the optical head is M, the optical density of thedetected light focused on the optical detector is obtained as 1/M² ofthe optical density of convergence light irradiated on the recordinglayer 3-2, and thus, a temperature rise amount on the optical detectorat the time of reproduction is obtained as ΔT_(read)/M² which is a roughestimate. In view of the fact that an upper limit value of opticaldensity, which can be irradiated on the optical detector, is convertedby the temperature rise amount, it is considered that the upper limitvalue is in order of ΔT_(read)/M²≦1° C. The image foaming magnificationof the detecting system in the optical head M is in order of 3 times to10 times in general, if the magnification M²≅10 is tentativelyestimated, it is necessary to set reproduction power so as to obtain:ΔT _(read) /ΔT _(write)≦20   (B-3)

Assuming that a duty ratio of recording pulses at the time of recordingis estimated as 50%, the following is required:[Optimal reproduction power]≧[Optimal recording power]/10   (B-4)

Therefore, in view of formulas (8) to (13) described later and the aboveformula (B-4), optimal reproduction power is assigned as follows:[Optimal reproduction power]<3×(0.65/NA)²×(V/6.6)   (B-5)[Optimal reproduction power]<3×(0.65/NA)²×(V/6.6)^(1/2)   (B-6)[Optimal reproduction power]<2×(0.65/NA)²×(V/6.6)   (B-7)[Optimal reproduction power]<2×(0.65/NA)²×(V/6.6)^(1/2)   (B-8)[Optimal reproduction power]<1.5×(0.65/NA)²×(V/6.6)   (B-9)[Optimal reproduction power]<1.5×(0.65/NA)²×(V/6.6)^(1/2)   (B-10)

(Refer to “3-2-E] Basic characteristics relating to thicknessdistribution of recording layer in the present embodiment for definitionof parameters”.) For example, when NA=0.65 and V=6.6 m/s, the followingis obtained:

[Optimal reproduction power]<3 mW,

[Optimal reproduction power]<2 mW, or

[Optimal reproduction power]<1.5 mW.

In reality, the optical detector is fixed as compared with the fact theinformation storage medium rotates and relatively moves, and thus, inconsideration of this fact, it is necessary to further set the optimalreproduction power to be in order of ⅓ or less of the value obtained inthe above formula. In the information recording/reproducing apparatusaccording to the present embodiment, a value of the reproduction poweris set to 0.4 mW.

3-2-C] Ideal Recording Film Structure in which a Principle of RecordingShown in the Present Embodiment is Easily Generated

A description will be given with respect to a method for “setting anenvironment” (recording film structure or shape) in which the aboveprinciple of recording is easily generated in the present embodiment.

As an environment in which an optical characteristic change inside ofthe above described recording layer 3-2 is likely to occur, the presentembodiment is featured in that a technical contrivance is carried out inrecording film structure or shape such as:

“in an area for forming the recording mark 9, a critical temperature atwhich an optical characteristic change is likely to occur is exceeded,and at a center part of the recording mark 9, a gasification(evaporation) temperature is not exceeded, and a surface of atransparent substrate 2-2 in the vicinity of the center part of therecording mark 9 does not exceed a thermal temperature”

The specific contents relating to the above description will bedescribed with reference to FIGS. 7A, 7B and 7C. In FIGS. 7A, 7B and 7C,the open (blank) arrow indicates an optical path of an irradiation laserlight beam 7, and the arrow of the dashed line indicates a thermal flow.A recording film structure shown in FIG. 7A indicates an environment inwhich an optical characteristic change inside of a recording layer 3-2corresponding to the present embodiment is most likely to occur. Thatis, in FIG. 7A, the recording layer 3-2 consisting of an organic dyerecording material has uniform thickness anywhere in the range shown informula (3) or formula (4) (where the thickness is sufficiently large),and receives irradiation of the laser light beam 7 in a directionvertical to the recording layer 3-2. As described in detail in “6-1)light reflection layer (material and thickness)”, a silver alloy is usedas a material for a light reflection layer 4-2 in the presentembodiment. A material including a metal with high light reflectionfactor, in general, has high thermal conductivity and heat radiationcharacteristics without being limited to the silver alloy. Therefore,although a temperature of the recording layer 3-2 is risen by absorbingthe energy of the irradiated laser light beam 7, a heat is radiatedtoward the light reflection layer 4-2 having heat radiationcharacteristics. Although a recording film shown in FIG. 7A is formedanywhere in a uniform shape, a comparatively uniform temperature riseoccurs inside of the recording layer 3-2, and a temperature differenceat points α, β, and γ at the center part is comparatively small.Therefore, when the recording mark 9 is formed, when a criticaltemperature at which an optical characteristic change at the points αand β occurs is exceeded, a gasification (evaporation) temperature isnot exceeded at the point a of the center part; and a surface of atransparent substrate (not shown) which exists at a position which isthe closest to the point α of the center part does not exceed a thermaldeformation temperature.

In comparison, as shown in FIG. 7B, a step is provided partly of therecording film 3-2. At the points δ and ε, the radiation of the laserlight beam 7 is subjected in a direction oblique to a direction in whichthe recording layer 3-2 is arrayed, and thus, an irradiation amount ofthe laser light beam 7 per a unit area is relatively lowered as comparedwith the point α of the center part. As a result, a temperature riseamount in the recording layer 3-2 at the points δ and ε is lowered. Atthe points δ and ε as well, thermal radiation toward the lightreflection layer 4-2 occurs, and thus, the arrival temperature at thepoints δ and ε is sufficiently lowered as compared with the point α ofthe center part. Therefore, a heat flows from the point β to the point αand a heat flows from the point α to the point β, and thus, atemperature difference at the points β and γ relevant to the point ax ofthe center part becomes very small. At the time of recording, atemperature rise amount at the points β and γ is low, and a criticaltemperature at which an optical characteristic change occurs is hardlyexceeded at the points β and α. As countermeasures against it, in orderto produce an optical characteristic change occurs at the points β and γ(in order to produce a critical temperature or more), it is necessary toincrease an exposure amount (recording power) of the laser light beam 7.In the recording film structure shown in FIG. 7B, a temperaturedifference at the point α of the center part relevant to the points βand γ is very large. Thus, when a current temperature has risen at atemperature at which an optical characteristic change occurs at thepoints β and γ, a gasification (evaporation) temperature is exceeded atthe point α of the center part or the surface of a transparent substrate(not shown) in the vicinity of the point α of the center part hardlyexceeds a thermal deformation temperature.

In addition, even if the surface of the recording layer 3-2 at the sideat which irradiation of the laser light beam 7 is subjected is verticalto the irradiation direction of the laser light beam 7 anywhere, in thecase where the thickness of the recording layer 3-2 changes depending ona location, there is provided a structure in which an opticalcharacteristic change inside of the recording layer 3-2 according to thepresent embodiment hardly occurs. For example, as shown in FIG. 7C, letus consider a case in which the thickness D1 of a peripheral part issignificantly small with respect to the thickness Dg of the recordinglayer 3-2 at the point α of the center part (for example, formula (2) orformula (4) is not satisfied). Even at the point α of the center part,although heat radiation toward the light reflection layer 4-2 occurs,the thickness Dg of the recording layer 3-2 is sufficiently large, thusmaking it possible to achieve heat accumulation and to achieve a hightemperature. In comparison, at the points ζ and η at which the thicknessD1 is significantly small, a heat is radiated toward the lightreflection layer 4-2 without carrying out heat accumulation, and thus, atemperature rise amount is small. As a result, heat radiation towardpoints β, δ, and ζ in order and heat radiation toward points γ, ε, and ηin order occurs as well as heat radiation toward the light reflectionlayer 4-2, and thus, as in FIG. 7B, a temperature difference at thepoint α of the center part relevant to points β and γ becomes verylarge. When an exposure amount of the laser light beam 7 (recordingpower) is increased in order to produce an optical characteristic changeat the points β and γ (in order to produce a critical temperature ormore), the gasification (evaporation) temperature at the point α of thecenter part is exceeded or the surface of the transparent substrate (notshown) in the vicinity of the point α of the center part easily exceedsa thermal deformation temperature.

Based on the contents described above, referring to FIGS. 8A, 8B and 8C,a description will be given with respect to: the contents of a technicalcontrivance in the present embodiment relating to the pre-grooveshape/dimensions for providing “setting of environment (structure orshape of a recording film)” in which a principle of recording accordingto the present embodiment is likely to occur; and the contents of atechnical contrivance in the present embodiment relating to a thicknessdistribution of the recording layer. FIG. 8A shows a recording filmstructure in a conventional write-once type information storage mediumsuch as CD-R or DVD-R; and FIGS. 8B and 8C each show a recording filmstructure in the present embodiment. In the invention, as shown in FIGS.8A, 8B and 8C, a recording mark 9 is formed in a pre-groove area 11.

3-2-D] Basic Characteristics Relating to Pre-Groove Shape/Dimensions inthe Present Embodiment

As shown in FIG. 8A, there have been many cases in which a pre-groovearea 11 is formed in a “V-groove” shape in a conventional write-oncetype information storage medium such as CD-R or DVD-R. In the case ofthis structure, as described in FIG. 7B, the energy absorptionefficiency of the laser light beam 7 is low, and the temperaturedistribution non-uniformity in the recording layer 3-2 becomes verylarge. The present embodiment is featured in that, in order to makeclose to an ideal state of FIG. 7A, a planar shape orthogonal to atraveling direction of the incident laser light beam 7 is provided inthe pre-groove area 11 at the side of at least the “transparentsubstrate 2-2”. As described with reference to FIG. 7A, it is desirablethat this planar area be as wide as possible. Therefore, the presentembodiment is featured in that the planar area is provided in thepre-groove area 11 and the width Wg of the pre-groove area 11 is widerthan the width W1 of a land area (Wg>W1). In this description, the widthWg of the pre-groove area and the width W1 of the land area are definedas their respective widths at a position at which there crosses a planehaving an intermediate height between a height at a planar position ofthe pre-groove area and a height at a position at which the land areabecomes the highest and an oblique surface in the pre-groove.

A discussion has been made using thermal analysis, data has beenrecorded in a write-once type information storage medium actuallyproduced as a prototype, substrate deformation observation due to asectional SEM (scanning type electronic microscope) image at theposition of the recording mark 9 has been made, and observation of thepresence or absence of a cavity generated due to gasification(evaporation) in the recording layer 3-2 has been repeated. As a result,it is found that advantageous effect is attained by widening the widthWg of the pre-groove area more significantly than the width W1 of theland area. Further, a ratio of the pre-groove area width Wg and the landarea width W1 is Wg:W1=6:4, and desirably, is greater than Wg:W1=7:3,whereby it is considered that a local optical characteristic change inthe recording layer 3-2 is likely to occur while the change is morestable at the time of recording. As described above, when a differencebetween the pre-groove area width Wg and the land area width W1 isincreased, a flat surface is eliminated from the top of the land area12, as shown in FIG. 8C. In the conventional DVD-R disc, a pre-pit (landpre-pit: not shown) is formed in the land area 12, and a format forrecording address information or the like in advance is realized here.Therefore, it is conditionally mandatory to form a flat area in the landarea 12. As a result, there has been a case in which the pre-groove area11 is formed in the “V-groove” shape. In addition, in the conventionalCD-R disc, a wobble signal has been recorded in the pre-groove area 11by means of frequency modulation. In a frequency modulation system inthe conventional CD-R disc, slot gaps (a detailed description of eachformat is given in detail) are not constant, and phase adjustment at thetime of wobble signal detection (PLL: synchronization of PLL (Phase LockLoop)) has been comparatively difficult. Thus, a wall face of thepre-groove area 11 is concentrated (made close to the V-groove) in thevicinity of a center at which the intensity of a reproducing focusingspot is the highest and a wobble amplitude amount is increased, wherebythe wobble signal detection precision has been guaranteed. As shown inFIGS. 8B and 8C, after the flat area in the pre-groove area 11 in thepresent embodiment has been widened, when the oblique surface of thepre-groove area 11 is shifted to the outside relatively than a centerposition of the reproducing focusing spot, a wobble detection signal ishardly obtained. The present embodiment is featured in that the width Wgof the pre-groove area described above is widened and the H formatutilizing PSK (Phase Shift Keying) in which slot gaps at wobbledetection is always fixedly maintained or the B format utilizing FSK(Frequency Shift Keying) or STW (Saw Tooth Wobble) are combined, wherebystable recording characteristics are guaranteed (suitable to high speedrecording or layering) at low recording power and stable wobble signaldetection characteristics are guaranteed. In particular, in the Hformat, in addition to the above combination, “a ratio of a wobblemodulation is lowered more significantly than that of a non-modulationarea”, thereby facilitating synchronization at the time of wobble signaldetection more significantly, and further, stabilizing wobble signaldetection characteristics more significantly.

3-2-E] Basic Characteristics Relating to Thickness Distribution ofRecording Layer 3-2 in the Present Embodiment

In the present description, as shown in FIGS. 8B and 8C, the thicknessin a portion at which the recording layer 3-2 in the land area 12 is thethickest is defined as recording layer thickness Dl in the land area 12;and a portion at which the recording layer 3-2 in the pre-groove area 11is the thickest is defined as recording layer thickness Dg in thepre-groove area. As has been described with reference to FIG. 7C, therecording layer thickness D1 in the land area is relatively increased,whereby a local optical characteristic change in the recording layer isstably likely to occur at the time of recording.

In the same manner as that described above, a discussion has been madeusing thermal analysis, data has been recorded in a write-once typeinformation storage medium actually produced as a prototype, substratedeformation observation and observation of the presence or absence of acavity generated due to gasification (evaporation) in the recordinglayer 3-2 by a sectional SEM (scanning type electronic microscope) imageat the position of the recording mark 9 have been made. As a result, ithas been found necessary to set a ratio between the recording layerthickness Dg in the pre-groove area and the recording layer thickness D1in the land area to be equal to or smaller than Dg:D1=4:1. Further,Dg:D1=3:1 is set, and desirably, Dg:D1=2:1 is set, thereby making itpossible to guarantee stability of a principle of recording in thepresent embodiment.

3-3) Recording Characteristics Common to Organic dye Recording Film inthe Present Embodiment

As one of “3-2-B] basic characteristics common to an organic dyerecording material in the present embodiment”, the present embodiment isfeatured by recording power control, as described in item [γ].

The formation of the recording mark 9 due to a local opticalcharacteristic change in the recording layer 3-2 occurs at atemperature, which is much lower than a plastic deformation temperatureof the conventional transparent substrate 2-2, at a thermaldecomposition temperature in the recording layer 3-2, or a gasification(evaporation) temperature. Thus, an upper limit value of recording poweris restricted so as not ensure that the transparent substrate 2-2locally exceeds a plastic deformation temperature at the time ofrecording or a thermal decomposition temperature or a gasification(evaporation) temperature is locally exceeded in the recording layer3-2.

In parallel to discussion using thermal analysis, by using an apparatusdescribed later in “4-1) Description of structure and characteristics ofreproducing apparatus or recording/reproducing apparatus in the presentembodiment” and by using a recording condition described later in “4-3)Description of recording condition in the present embodiment”, there hasbeen made a demonstration of a value of optimal power in the case whererecording has been carried out in a principle of recording shown in thepresent embodiment. A numerical aperture (NA) value of an objective lensin the recording/reproducing apparatus used in a demonstration test hasbeen 0.65, and a line speed at the time of recording has been 6.61 m/s.As a value of recording power (Peak Power) defined later in “4-3)Description of recording condition in the present embodiment”, it hasbeen found that:

Gasification (evaporation) occurs with most of an organic dye recordingmaterial at 30 mW, and a cavity occurs in a recording mark;

A temperature of the transparent substrate 2-2 at a position in thevicinity of the recording layer 3-2 significantly exceeds a glasstransition temperature;

A temperature of the transparent substrate 2-2 at a position in thevicinity of the recording layer 3-2 reaches a plastic deformationtemperature (glass transition temperature) at 20 mW;

15 mW or less is desirable in consideration of a margin such as surfacepre-warping or recording power change of an information storage medium.

The “recording power” described above denotes a sum of exposure amountirradiated to the recording layer 3-2. The optical energy density at acenter part of a focusing spot and at a portion at which the opticalintensity density is the highest is obtained as parameters targeted fordiscussion in the present embodiment. The focusing spot size isinversely proportional to the NA value, and thus, the optical energydensity at the center part of the focusing spot increases in proportionto a square of the NA value. Therefore, the current value can beconverted to a value of optimal recording power in the B formatdescribed later or another format (another NA value) shown in FIG. 1(D3) by using a relational formula below:[Recording power applicable to different NA values]=[Recording powerwhen NA=0.65]×0.65² /NA ²   (5)

Further, optimal recording power changes depending on a line speed V inphase change type recording material. In general, it is said thatoptimal recording power changes in proportion to a ½ square of a linespeed V in phase change type recording material, and changes inproportion to a line speed V in organic dye recording material.Therefore, a conversion formula of optimal recording power considering aline speed V, obtained by extending formula (5), is obtained as follows:[General recording power]=[Recording power when NA=0.65; 6.6m/s]×(0.65/NA)²×(V/6.6)   (6), or[General recording power]=[Recording power when NA=0.65; 6.6m/s]×(0.65/NA)²×(V/6.6)^(1/2)   (7)

When the above discussion result is summarized, as recording power forguaranteeing a principle of recording shown in the present embodiment,it is desirable to set an upper limit value such as:[Optimal recording power]<30×(0.65/NA)²×(V/6.6)   (8)[Optimal recording power]<30×(0.65/NA)²×(V/6.6)^(1/2)   (9)[Optimal recording power]<20×(0.65/NA)²×(V/6.6)   (10)[Optimal recording power]<20×(0.65/NA)²×(V/6.6)^(1/2)   (11)[Optimal recording power]<15×(0.65/NA)²×(V/6.6)   (12)[Optimal recording power]<15×(0.65/NA)²×(V/6.6)^(1/2)   (13)

From among the above formulas, a condition for formula (8) or formula(9) is obtained as a mandatory condition; a target condition for formula(10) or formula (11) is obtained; and a condition for formula (12) orformula (13) is obtained as a desirable condition.

3-4) Description of Characteristics Relating to “H-L” Recording Film inthe Present Embodiment

A recording film having characteristics that a light reflection amountin a recording mark 9 is lower than that in an unrecorded area isreferred to as an “H-L” recording film. In contrast, a recording film inwhich the above light reflection amount is high is referred to as an“L-H” recording film. Among them, with respect to the “H-L” recordingfilm, the present embodiment is featured in that:

an upper limit value is provided at a ratio of absorbance at areproduction wavelength relevant to absorbance at a λ_(max write)position of light absorption spectra; and

a light absorption spectra profile is changed to form a recording mark.

A detailed description relating to the above contents will be given withreference to FIGS. 9 and 10. In the “H-L” recording film in the presentembodiment, as shown in FIG. 9, a wavelength of λ_(max write) is shorterthan a use wavelength utilized for recording/reproduction (in thevicinity of 405 nm). As is evident from FIG. 10, in the vicinity of awavelength of λ_(max write), a change of absorbance is small between anunrecorded portion and a recorded portion. If a change of absorbance issmall between the unrecorded portion and the recorded portion, a largereproduction signal amplitude cannot be obtained. Even if a wavelengthchange of a recording or reproducing laser light source occurs, in viewof the fact that recording or reproduction can be stably carried out, inthe present embodiment, as shown in FIG. 9, a design of the recordingfilm 3-2 is made so that a wavelength of λ_(max write) arrives at theoutside ranging from 355 nm to 455 nm, i.e., arrives at the shorterwavelength side than 355 nm.

The relative absorbance at 355 nm, 455 nm, and 405 nm described in“Chapter 0: Description of Relationship between Use Wavelength and thePresent Embodiment” when the absorbance at a position of λ_(max write)defined in “2-1) Difference in principle of recording/recording filmstructure and difference in basic concept relating to reproductionsignal generation”, is defined as Ah₃₅₅, Ah₄₅₅, and Ah₄₀₅.

In the case where of Ah₄₀₅=0.0, the light reflection factor from arecording film in an unrecorded state coincides with that at 405 nm inthe light reflection layer 4-2. A light reflection factor of the lightreflection layer 4-2 will be described later in detail in the section“6-1) Light reflection layer”. Hereinafter, a description will be givenwith respect to the fact that the light reflection factor of the lightreflection layer 4-2 is defined as 100% for the sake of simplification.

In the write-once type information storage medium using an “H-L”recording film in the present embodiment, a reproduction circuit is usedin common to a case of using a read-only type information storage medium(HD DVD-ROM disc) in the case of a one-sided single layer film.Therefore, in this case, an optical reflection factor is defined as 45%to 85% in accordance with a light reflection factor of the reflectiononly information storage medium (HD DVD-ROM disc) of a one-sided singlelayer film. Therefore, it is necessary to set the light reflectionfactor at an unrecorded position to 40% or more. Because 1−0.4=0.6, itis possible to intuitively understand whether or not the absorbanceAh₄₀₅ at 405 nm may be set:Ah₄₀₅≦0.6   (14)

In the case where formula (14) above is met, it is possible to easilyunderstand that the light reflection factor can be set to 40% or more.Thus, in the present embodiment, an organic dye recording material,which meets formula (14) in an unrecorded location, is selected. Theabove formula (14) assumes that, in FIG. 9, the light reflection factoris obtained as 0% when the light reflection layer 4-2 is reflected overthe recording layer 3-2 with a light beam having a wavelength ofλ_(max write). However, in reality, at this time, the light reflectionfactor is not obtained as 0%, and has a certain degree of lightreflection factor. Thus, strictly, there is a need for correctionrelevant to formula (14). In FIG. 9, if the light reflection factor isdefined as Rλ_(max write) when the light reflection layer 4-2 has beenreflected over the recording layer 3-2 with a light beam having awavelength of λ_(max write), a strict conditional formula in which thelight reflection factor at an unrecorded position is set to 40% or moreis obtained as follows:I−Ah ₄₀₅×(1−Rλ _(max write))≧0.4   (15)

In the “H-L” recording layer, in many cases, Rλ_(max write))≧0.25, andthus, formula (15) is established as follows:Ah₄₀₅≦0.8   (16)

In the “H-L” recording film according to the present embodiment, it isconditionally mandatory to meet formula (16). Characteristics of theabove formula (14) has been provided, and further, a detailed opticalfilm design has been made under a condition that the film thickness ofthe recording layer 3-2 meets the condition for formula (3) or formula(4), in consideration of a variety of margins such as a film thicknesschange or a wavelength change of reproduction light. As a result, it hasbeen found desirable that:Ah₄₀₅≦0.3   (17)

Assuming that formula (14) is established, when:Ah₄₅₅≦0.6   (18)orAh₃₅₅<0.6   (19),

the recording/reproducing characteristics are more stable. This isbecause, in the case where formula (14) meets any of at least formulas(18) and (19) when formula (14) is established, the value of Ah becomes0.6 or less in the range of 355 nm to 405 nm or in the range of 405 nmto 455 nm (occasionally in the range of 355 nm to 455 nm), and thus,even if a fluctuation occurs at a light emission wavelength of arecording laser light source (or a reproducing laser light source), avalue of absorbance does not change drastically.

As a specific principle of recording of the “H-L” recording film in thepresent embodiment, there is utilized a phenomenon of “array changebetween molecules” or “molecular structure change in molecule” in arecording mechanism listed in item [α] in “3-2-B] Basic feature commonto organic dye recording material in the present embodiment” which hasbeen described as a specific principle of recording of the “H-L”recording film in the present embodiment. As a result, as described inthe above item (2), a light absorption spectrum profile is changed. Thelight absorption spectrum profile in a recording mark in the presentembodiment is indicated by the solid line shown in FIG. 10, and thelight absorption spectrum profile in an unrecorded location issuperimposed by the dashed line, thereby making it possible to comparethese profiles with each other. In the present embodiment, the lightabsorption spectrum profile in the recording mark changes comparativelybroadly, and there is a possibility that a molecular structure change inmolecules occurs and partial precipitation (coal tar) of carbon atomsoccurs. The present embodiment is featured in that a value of awavelength λ1 _(max) at which the absorbance in the recording markbecomes maximal is made closer to a reproduction wavelength of 405 nmthan a value of a wavelength λ_(max) write at an unrecorded position,thereby generating a reproduction signal in the “H-L” recording film. Inthis manner, the absorbance at the wavelength λ1 _(max) at which theabsorbance is the highest becomes smaller than “1”, and a value of theabsorbance Al₄₀₅ at a reproduction wavelength of 405 nm becomes greaterthan a value of Ah₄₀₅. As a result, a total light reflection factor in arecording mark is lowered.

In the H format in the present embodiment, as a modulation system, thereis employed ETM (Eight to Twelve: 8-bit data code is converted to12-channel bit) and RLL (1, 10) (Among a code train after modulated, aminimum inversion length relevant to a 12-channel bit length T is 2 T,and a maximum inversion length is 11 T). Where performance evaluation ofa reproduction circuit described later in “4-2) Description ofreproducing circuit in the present embodiment) is carried out, in orderto stably carry out reproduction by the reproducing circuit, it has beenfound necessary to meet that a ratio of [differential valueI11≡I_(11H)-I_(11L) between the I_(11H) and reproduction signal amountI_(11L) from a recording mark having a sufficiently long length (11 T)]is:I ₁₁ /I _(11H)≧0.4   (20) or preferably,I ₁₁ /I _(11H)>0.2   (21)

In the present embodiment, a PRML method is utilized at the time ofsignal reproduction recorded at high density, and a signal processorcircuit and a state transition chart shown in FIGS. 15 to 17 is used (Adetailed description is given later). In order to precisely carry outdetection in accordance with a PRML technique, the linearity of areproduction signal is requested. The characteristic of the signalprocessor circuit shown in FIGS. 15 and 16 has been analyzed based onthe state transition chart shown in FIG. 17, in order to ensure thelinearity of the above reproduction signal. As a result, it has beenfound necessary to meet that a ratio relevant to the above I₁₁ of avalue when a recording mark having a length of 3 T and a reproductionsignal amplitude from a repetition signal of an unrecorded space isdefined as I₃ meets:I ₃ /I ₁₁>0.35   (22); or desirably,I ₃ /I ₁₁>0.2   (23)

In view of a condition for the above formula (16), the presentembodiment is technically featured in that a value of Al₄₀₅ has been setso as to meet formulas (20) and (21). Referring to formula (16), thefollowing is obtained:1−0.3=0.7   (24)

In view of formula (24), from a correlation with formula (20), thefollowing condition is derived:(Al₄₀₅−0.3)/0.7≧0.4, that is,Al₄₀₅≧0.58   (25)

Formula (25) is a formula derived from a very coarse result ofdiscussion, and is merely shown as a basic concept. Because the Ah₄₀₅setting range is specified in accordance with formula (16), in thepresent embodiment, at least a condition for Al₄₀₅ is mandatory as:Al₄₀₅>0.3   (26)

As a method for selecting an organic dye material suitable to a specific“H-L” recording layer, there is selected an organic dye material forwhich, in the present embodiment, based on an optical film design, arefractive factor range in an unrecorded state is n₃₂=1.3 to 2.0; theabsorption coefficient range is k₃₂=0.1 to 0.2, desirably n₃₂=1.7 to1.9; the absorption coefficient range is k₃₂=0.15 to 0.17, and a seriesof conditions described above are met.

In the “H-L” recording film shown in FIG. 9 or 10, in light absorptionspectra in an unrecorded area, although a wavelength of λ_(max write) isshorter than a wavelength of reproduction light or recording/reproducinglight (for example, 405 nm), the wavelength of λ_(max write) may belonger than a wavelength of reproduction light or recording/reproducinglight (for example, 405 nm), without being limited thereto.

In odder to meet the above formula (22) or formula (23), the thicknessDg of the recording layer 3-2 is influenced. For example, if thethickness Dg of the recording layer 3-2 significantly exceeds anallowable value, optical characteristics of only a part coming intocontact with the transparent substrate 2-2 in the recording layer 3-2are changed as a state that follows forming of the recording mark 9,whereby the optical characteristics of a portion coming into contactwith the light reflection layer 4-2 adjacent to its location areobtained as a value equal to that in the unrecorded area. As a result, areproduction light amount change is lowered, and a value of I₃ informula (22) or formula (23) is reduced, and a condition for formula(22) or formula (23) cannot be met. Therefore, in order to meet formula(22), as shown in FIGS. 8B and 8C, it is necessary to make a change tothe optical characteristics of a portion which comes into contact withthe light reflection layer 4-2 in the recording mark 9. Further, if thethickness Dg of the recording layer 3-2 significantly exceeds anallowable value, a temperature gradient occurs in the thicknessdirection in the recording layer 3-2 when the recording mark is formed.Then, before reaching the optical characteristic change temperature at aportion coming into contact with the light reflection layer 4-2 in therecording layer 3-2, a gasification (evaporation) temperature of aportion coming into contact with the transparent substrate 2-2 isexceeded or a thermal deformation temperature is exceeded in thetransparent substrate 2-2. For the above reason, in the presentembodiment, in order to meet formula (22), the thickness Dg of therecording layer 3-2 is set to “3 T” or less based on the discussion ofthermal analysis; and a condition meeting formula (23) is such that thethickness Dg of the recording layer 3-2 is set to “3×3 T” or less.Basically, in the case where the thickness Dg of the recording layer 3-2is equal to or smaller than “3 T”, although formula (22) can be met, thethickness may be set to “T” or less in consideration of effect of a tiltdue to a facial motion or warping of the write-once type informationstorage medium or a margin relevant to a focal blurring. Inconsideration of a result obtained by formulas (1) and (2) describedpreviously, the thickness Dg of the recording layer 3-2 in the presentembodiment is set in the range assigned in a required minimum conditionthat:9 T≧Dg≧λ/8n ₃₂   (27)and in a desired condition that:3 T≧Dg≧λ/4n ₃₂   (28)

Without being limited thereto, the severest condition can be defined as:T≧Dg≧λ/4n ₃₂   (29)

As described later, a value of the channel bit length T is 102 nm in theH format, and is 69 nm to 80 nm in the B format. Thus, a value of 3 T is306 nm in the H format and is 207 nm to 240 nm in the B format. A valueof 9 T is 918 nm in the H format and is 621 nm to 720 nm in the Bformat. Here, although an “H-L” recording film has been described, theconditions for formulas (27) to (29) can be applied to an “L-H”recording film without being limited thereto.

Chapter 4: Description of Reproducing Apparatus or Recording/ReproducingApparatus and Recording Condition/Reproducing Circuit

4-1) Description of Structure and Characteristics of ReproducingApparatus or Recording/Reproducing Apparatus in the Present Embodiment

FIG. 11 shows an illustration of a structure in an embodiment of aninformation recording/reproducing apparatus. In FIG. 11, an upper sideof a control unit 143 mainly indicates an information recording controlsystem for an information storage medium. In the embodiment of theinformation reproducing apparatus, a structure excluding the informationrecording control system in FIG. 11 corresponds to the above structure.In FIG. 11, the arrow drawn by the thick solid line indicates a flow ofmain information which designates a reproduction signal or a recordingsignal; the arrow of the thin solid line denotes a flow of information;the arrow of the one-dotted chain line denotes a reference clock line;and the arrow of the thin dashed line denotes a command indicatingdirection.

An optical head (not shown) is arranged in an informationrecording/reproducing unit 141 shown in FIG. 11. In the presentembodiment, although a wavelength of a light source (semiconductorlaser) used in the optical head is 405 nm, the present embodiment is notlimited thereto, and there can be used a light source having a usewavelength equal to or shorter than 620 nm or 530 nm or a light sourceranging from 355 nm to 455 nm, as described previously. In addition, twoobjective lenses used to focus the light beam having the abovewavelength onto the information storage medium may be incorporated inthe optical head. In the case where a recording/reproducing operation iscarried out with respect to an information storage medium in the Hformat, an objective lens having a NA value of 0.65 is used. A structureis provided such that, in the case where a recording/reproducingoperation is carried out with respect to an information storage mediumin the B format, an objective lens having NA=0.85 is used. As anintensity distribution of incident light immediately before the light isincident to an objective lens, the relative intensity at the peripheryof the objective lens (at the boundary position of an aperture) when thecenter intensity is set to “1” is referred to as “RIM Intensity”. Avalue of the RIM intensity in the H format is set in the range of 55% to70%. At this time, a wave surface aberration amount in the optical headis optically designed so as to be 0.33λ (0.33λ or less) with respect toa use wavelength λ.

In the present embodiment, a partial response maximum likelihood (PRML)is used for information reproduction to achieve high density of aninformation storage medium (FIG. 1, point [A]). As a result of a varietyof tests, when PR(1, 2, 2, 2, 1) is used as a PR class to be used, linedensity can be increased and the reliability of a reproduction signalcan be improved (i.e., demodulation reliability can be improved) when aservo correction error such as a focal blurring or a track shift hasoccurred. Thus, in the present embodiment, PR(1, 2, 2, 2, 1) is employed(FIG. 1, point [A1]). In the present embodiment, a channel bit patternafter modulated is recorded in an information storage medium inaccordance with a (d, k; m, n) modulation rule (In the above describedmethod, this denotes RLL(d, k) of m/n modulation). Specifically, ETM(Eight to Twelve Modulation) for converting 8-bit data to a 12-channelbit (m=8, n=12) is employed as a modulation system, and a condition ofRLL (1, 10) in which a minimum value having continuous “0”s is definedas d=1, and a maximum value is defined as k=10 as a run length limitedRLL restriction for apply limitation to a length that follows “0” in thechannel bit pattern after modulated must be met. In the presentembodiment, in order to achieve high density of an information storagemedium, a channel bit gap is reduced to the minimum. As a result, forexample, after a pattern “101010101010101010101010” which is arepetition of a pattern of d=1 has been recorded in the informationstorage medium, in the case where the data is reproduced in aninformation recording/reproducing unit 141, the data is close to ashutdown frequency having MTF characteristics of a reproducing opticalsystem, and thus, a signal amplitude of a reproduced raw signal isformed in a shape almost hidden by noise. Therefore, a partial responsemaximum likelihood (PRML) technique is used as a method for thusreproducing a recording mark or a pit, which has been dense up to thevicinity of a limit of the MTF characteristics (shutdown frequency).That is, a signal reproduced from the information recording/reproducingunit 141 receives reproducing waveform correction by a PR equalizercircuit 130. A signal having passed through the PR equalizer circuit 130is sampled by converting a signal after passing through the PR equalizercircuit 130 to a digital amount in accordance with a timing of areference clock 198 sent from a reference clock generating circuit 160;the sampled signal is converted to a digital data by an AD converter169; and a Viterbi decoding process is carried out in a Viterbi decoder156. The data after Viterbi-decoded is processed as data, which iscompletely similar to binary data at a conventional slice level. In thecase where the PRML technique has been employed, if a sampling timingobtained by the AD converter 169 is shifted, an error rate of the dataafter Viterbi decoded increases. Therefore, in order to enhanceprecision of the sampling timing, the information reproducing apparatusor information recording/reproducing apparatus according to the presentembodiment has another sampling timing sampling circuit in particular(combination of Schmidt trigger binarizing circuit 155 and PLL circuit174). This Schmidt trigger circuit 155 has a specific value (forwarddirection voltage value of diode in actuality) at a slice referencelevel for binarizing, and is featured in that binarizing is provide onlywhen the specific width has been exceeded. Therefore, for example, asdescribed above, in the case where a pattern of“101010101010101010101010” has been input, a signal amplitude is verysmall, and thus, switching of binarizing does not occur. In the casewhere “1001001001001001001001” or the like, for example, being a patternof a rarer fraction than the above, has been input, an amplitude of areproducing raw signal increases, and thus, the polarity switching of abinary signal occurs in accordance with a timing of “1” by a Schmidttrigger binarizing circuit 155. In the present embodiment, an NRZI (NonReturn to Zero Invert) technique is employed, and a position of “1” ofthe above pattern coincides with an edge section (boundary section) of arecording mark or a pit.

A PLL circuit 174 detects a shift in frequency and phase between abinary signal which is an output of this Schmidt trigger binarizingcircuit 155 and a signal of a reference clock 198 sent from a referenceclock generating circuit 160 to change the frequency and phase of theoutput clock of the PLL circuit 174. A reference clock generatingcircuit 160 applies a feedback to (a frequency and a phase) of areference clock 198 so as to lower an error rate after Viterbi decoded,by using an output signal of this PLL circuit 174 and decodingcharacteristic information on a Viterbi decoder 156 and a convergencelength (information on (distance to convergence)) in a path metricmemory in the Viterbi decoder 156, although is not specifically shown).The reference clock 198 generated by this reference clock generatingcircuit 160 is utilized as a reference timing at the time ofreproduction signal processing.

A sync code position sampling unit 145 serves to detect the presence andposition of a sync code, which coexists in an output data train of theViterbi decoder 156 and to sample a start position of the above outputdata. While this start position is defined as a reference, a demodulatorcircuit 152 carries out a demodulating process with respect to datatemporarily stored in a shift resistor circuit 170. In the presentembodiment, the above temporarily stored data is returned to itsoriginal bit pattern with reference to a conversion table recorded in ademodulating conversion table recording unit 154 on 12-channel bit bybit basis. Then, an error correcting process is performed by an ECCdecoding circuit 162, and descrambling is carried out by a descramblingcircuit 159. Address information is recorded in advance by wobblemodulation in a recording type (rewritable type or write-once type)information storage medium according to the present embodiment. A wobblesignal detecting unit 135 reproduces this address information (i.e.,judges the contents of a wobble signal), and supplies informationrequired to provide an access to a desired location to the control unit143.

A description will be given with respect to an information recordingcontrol system provided at the upper side than the control unit 143.After data ID information has been generated from a data ID generatingunit 165 in accordance with a recording position on an informationstorage medium, when copy control information is generated by a CPR_MAIdata generating unit 167, a variety of information on data ID, TED,CPR_MAI, and EDC is added to information to be recorded by a data ID,TED, CPR_MAI, and EDC adding unit 168. After the added information hasbeen descrambled by the descrambling circuit 157, an ECC block is formedby an ECC encoding circuit 161, and the ECC block is converted to achannel bit pattern by a modulating circuit 151. A sync code is added bya sync code generating/adding unit 146, and data is recorded in aninformation storage medium in the information recording/reproducing unit141. At the time of modulation, DSV values after modulated aresequentially calculated by a DSV (Digital Sum Value) calculating unit148, and the serially calculated values are fed back to code conversionafter modulated.

FIG. 12 shows a detailed structure of peripheral portions including thesync code position detector unit 145 shown in FIG. 11. A sync code iscomposed of a sync position detecting code section and a variable codesection having a fixed pattern. From the channel bit pattern output froma Viterbi decoder, a sync position detecting code detector unit 182detects a position of a sync position detecting code section having theabove fixed pattern. Variable code transfer units 183 and 184 sampledata on a variable code which exists before and after the detectedposition, and judge in which sync frame in a sector the sync code ispositioned, the sync code being detected by an identifying unit 185 fordetecting a sync position having the above fixed pattern. Userinformation recorded on an information storage medium is sequentiallytransferred in order of a shift register circuit 170, a demodulationprocessing unit 188 in a demodulator circuit 152, and an ECC decodingcircuit 162.

In the present embodiment, in the H format, the high density of theinformation storage medium is achieved (in particular, line density isimproved) by using the PRML system for reproduction in a data area, adata lead-in area, and a data lead-out area. In addition, compatibilitywith a current DVD is ensured and reproduction stability is ensured byusing a slice level detecting system for reproducing in a system lead-inarea and a system lead-out area. (A detailed description will be givenlater in “Chapter 7: Description of H Format”.)

4-2) Description of Reproducing Circuit in the Present Embodiment

FIG. 13 shows an embodiment of a signal reproducing circuit using aslice level detecting system used at the time of reproduction in asystem lead-in area and a system lead-out area. A quadrature opticaldetector 302 in FIG. 13 is fixed into the optical head, which exists inthe information recording/reproducing unit 141 in FIG. 11. Hereinafter,a signal having taken a sum of detection signals obtained from opticaldetecting cells 1 a, 1 b, 1 c, and 1 d of the quadrature opticaldetector 302 is referred to as a “lead channel 1 signal”. From apreamplifier 304 to a slicer 310 in FIG. 13 corresponds to a detailedstructure in the slice level detecting circuit 132 in FIG. 11. Areproduction signal obtained from an information storage medium issubjected to a waveform equalizing process by a pre-equalizer 308 afterthe signal has passed through a high path filter 306 which shuts out afrequency component lower than a reproduction signal frequencybandwidth. According to testing, it has found that this pre-equalizer308 minimizes a circuit scale by using a 7-tap equalizer and can detecta reproduction signal precisely. Thus, in the present embodiment, the7-tap equalizer is used. A VFO circuit/PLL 312 in FIG. 13 corresponds tothe PLL circuit 174 in FIG. 11; and a demodulating/ECC decoding circuit314 in FIG. 13 corresponding to the decoding circuit 152 and the ECCdecoding circuit 162 in FIG. 11.

FIG. 14 shows a detailed structure in a circuit of the slicer 310 inFIG. 13. A binary signal after sliced is generated by using a comparator316. In response to an inverting signal of binary data after binarizedis set at a slice level at the time of binarizing. In the presentembodiment, a cutoff frequency of this low-pass filter is set to 5 KHz.When this cutoff frequency is high, a slice level change is fast, andthe low-pass filter is affected by noise. In contrast, if a cutofffrequency is low, a slice level response is slow, and thus, the filteris affected by dust or scratch on the information storage medium. Thecutoff frequency is set to 5 KHz in consideration of a relationshipbetween RLL(1, 10) and a reference frequency of a channel bit describedpreviously.

FIG. 15 shows a signal processor circuit using a PRML detectingtechnique used for signal reproduction in a data area, a data lead-inarea, and a data lead-out area. A quadrature optical detector 302 inFIG. 15 is fixed into the optical head, which exists in the informationrecording/reproducing unit 141 in FIG. 11. Hereinafter, a signal havingtaken a sum of detection signals obtained from the optical detectingcells 1 a, 1 b, 1 c, and 1 d of the quadrature optical detector 302 isreferred to as a “lead channel 1 signal”. A derailed structure in the PRequalizer circuit 130 in FIG. 11 is composed of circuits from apreamplifier 304 to a tap controller 332, an equalizer 330, and anoffset canceller 336 in FIG. 15. A PLL circuit 334 in FIG. 15 is a partin the PR equalizer circuit 130, and denotes an element other than theSchmidt trigger binarizing circuit 155. A primary cutoff frequency of ahigh path filter circuit 306 in FIG. 15 is set at 1 KHz. A pre-equalizercircuit 308 uses a 7-tap equalizer in the same manner as that in FIG. 13(because the use of the 7-tap equalizer minimizes a circuit scale andcan detect a reproduction signal precisely). A sample clock frequency ofan A/D converter circuit 324 is set to 72 MHz, and a digital output isproduced as an eight-bit output. In the PRML detecting technique, if areproduction signal is affected by a level change (DC offset) of itsentire signal, an error is likely to occur at the time of Viterbidemodulation. In order to eliminate such an effect, there is provided astructure of correcting an offset by the offset canceller 336 using asignal obtained from an equalizer output. In the embodiment shown inFIG. 15, an adaptive equalizing process is carried out in the PRequalizer circuit 130. Thus, a tap controller for automaticallycorrecting tap coefficients in the equalizer 330 is utilized byutilizing an output signal of the Viterbi decoder 156.

FIG. 16 shows a structure in the Viterbi decoder 156 shown in FIG. 11 or15. A branch metric relevant to all branches, which can be predicted inresponse to an input signal, is calculated by a branch metriccalculating unit 340, and the calculated value is sent to an ACS 342.The ACS 342 is an acronym of Add Compare Select, which calculates a pathmetric obtained by adding branch metrics in response to each of thepasses which can be predicted in the ACS 342 and transfers thecalculation result to a path metric memory 350. At this time, in the ACS342, a calculating process is carried out with reference to theinformation contained in the path metric memory 350. A path memory 346temporarily stores a value of the path metric corresponding to each path(transition) state and such each path, which can be predicted in thememory 346, the value being calculated by the ACS 342. An output switchunit 348 compares a path metric corresponding to each path, and selectsa path when a path metric value becomes minimal.

FIG. 17 shows a state change in PR(1, 2, 2, 2, 1) class in the presentembodiment. A change of a state which can be obtained in the PR(1, 2, 2,2, 1) class can be made as only a change shown in FIG. 17, and a pathwhich can exist (which can be predicted) at the time of decoding isidentified in the Viterbi decoder 156 based on a transition chart inFIG. 17.

4-3) Description of Recording Condition in the Present Embodiment

“A description of optimal recording power (peak power) in the presentembodiment has been given in “3-3) Recording characteristics common toorganic dye recording film in the present embodiment”. Referring to FIG.18, a description will be given with respect to a recording waveform(exposure condition at the time of recording) used when the optimalrecording power is checked.

The exposure levels at the time of recording have four levels ofrecording power (peak power), bias power 1, bias power 2, and bias power3. When a long (4T or more) recording mark 9 is formed, modulation iscarried out in the form of multi-pulses between recording power (peakpower) and bias power 3. In the present embodiment, in any of the Hformat and B format systems, a minimum mark length relevant to a channelbit length T is obtained as 2T. In the case where this minimum mark of2T is recorded, one write pulse of recording power (peak power) afterbias power 1 is used as shown in FIG. 18, and bias power 2 istemporarily obtained immediately after the write pulse. In the casewhere a 3T recording mark 9 is recorded, bias power 2 is temporarilyused after exposing two write pulses, a first pulse and a last pulse ofrecording power (peak power) level that follows bias power 1. In thecase where a recording mark 9 having a length of 4T or more is recorded,bias power 2 is used after multi-pulse and write pulse exposure.

The vertical dashed line in FIG. 18 shows a channel clock cycle. In thecase where a 2T minimum mark is recorded, the laser power is raised at aposition delayed by T_(SFP) from a clock edge, and fallen at a position,which is backward by T_(ELP) from an edge of a succeeding clock. A cycleduring which the laser power is set at bias power 2 is defined asT_(LC). Values of T_(SFP), T_(ELP), and T_(LC) are recorded in physicalformat information PFI contained in a control data zone CDZ as describedlater in the case of the H format. In the case where a 3T or more longrecording mark is formed, the laser power is risen at a position delayedby T_(SFP) from a clock edge, and lastly, ended with a last pulse.Immediately after the last pulse, the laser power is kept at the biaspower 2 during a period of T_(LC). Shift times from a clock edge to arise/fall timing of the last pulse are defined as T_(SLP), T_(ELP). Inaddition, a shift time from a clock edge to a fall timing of the lastpulse is defined as T_(EFP), and further, an interval of a single pulseof a multi-pulse is defined as T_(MP).

Each of intervals T_(ELP)-T_(SFP), T_(MP), T_(ELP)-T_(SLP), and T_(LC)is defined as a half-value wide relevant to a maximum value, as shown inFIG. 19. In addition, in the present embodiment, the above parametersetting range is defined as follows:0.25T≦T_(SFP)≦1.50T   (30)0.00T≦T_(ELP)≦1.00T   (31)1.00T≦T_(EFP)≦1.75T   (32)−0.10T≦T _(SLP)≦1.00T   (33)0.00T≦T_(LC)≦1.00T   (34)0.15T≦T_(MP)≦0.75T   (35)

Further, in the present embodiment, the values of the above describedparameters can be changed as shown in FIGS. 20A, 20B and 20C accordingto a recording mark length (Mark Length) and the immediatelypreceding/immediately succeeding space length (Leading/Trailing spacelength). FIGS. 21A, 21B and 21C each shows parameter values when optimalrecording power of the write-once type information storage mediumrecorded in a principle of recording shown in the present embodiment hasbeen checked, as described in the section “3-3) Recordingcharacteristics common to organic dye recording film in the presentembodiment”. At this time, the values of bias power 1, bias power 2, andbias power 3 are 2.6 mW, 1.7 mW, and 1.7 mW, and reproduction power is0.4 mW.

Chapter 5: Specific Description of Organic Dye Recording Film in thePresent Embodiment 5-1) Description of Characteristics Relating to “L-H”Recording Film in the Present Embodiment

A description will be given with respect to an “L-H” recording filmhaving characteristics in which a light reflection amount is lowered ina recording mark as compared with that in an unrecorded area. From amongprinciples of recording described in “3-2-B] Basic characteristicscommon to organic dye recording material in the present embodiment”, aprinciple of recording in the case of using this recording film mainlyutilizes any of:

Chromogenic characteristic change;

Change of electron structure (electron orbit) relevant to elements whichcontribute to chromogenic phenomenon [discoloring action or the like];and

Array change between molecules, and changes characteristics of lightabsorption spectra. The “L-H” recording film is featured in that thereflection amount range in an unrecorded location and a recordedlocation has been specified in view of characteristics of a read-onlytype information storage medium having a one-sided dual layeredstructure. FIG. 22 shows a light reflection factor range in anunrecorded area (non-recording portion) of the “H-L” recording film andthe “L-H” recording film according to the present embodiment. In thepresent embodiment, the lower limit value δ of the reflection factor atthe non-recording portion of the “H-L” recording film is specified so asto be higher than an upper limit value γ at the non-recording portion ofthe “L-H” recording film. When the above information storage medium hasbeen mounted on an information recording/reproducing apparatus or aninformation reproducing apparatus, a light reflection factor of thenon-recording portion is measured by the slice level detector unit 132or the PR equalizer circuit 130 shown in FIG. 11, thereby making itpossible to judge whether the film is the “H-L” recording film or “L-H”recording film, and thus, making it very easy to judge type of recordingfilm. Measurement has been carried out while producing the “H-L”recording film and the “L-H” recording film under a changedmanufacturing condition, when a light reflection factor α between thelower limit value δ at the non-recording portion of the “H-L” recordingfilm and the upper limit value γ at the non-recording portion of the“L-H” recording film is set in the range of 32% to 40%. As a result, ithas been found that high manufacturing performance of the recording filmis obtained and medium cost reduction is facilitated. After an opticalreflection factor range 801 of a non-recording portion (“L” portion) ofthe “L-H” recording film is made coincident with a light reflectionfactor range 803 of a one-sided double recording layer in the read-onlytype information storage medium, when a light reflection factor range802 of a non-recording portion (“H” portion”) of the “H-L” recordingfilm is made coincident with a light reflection factor range 804 of aone-sided single layer in the read-only type information storage medium,a reproducing circuit of the information reproducing apparatus can beused in common to be well compatible with the read-only type informationstorage medium, and thus, the information reproducing apparatus can beproduced inexpensively. Measurement has been carried out while producingthe “H-L” recording film and the “L-H” recording film under a variety ofchanged manufacturing conditions, in order to facilitate price reductionof a medium while improving the manufacturing performance of therecording film. As a result, the lower limit value β of the lightreflection factor of the non-recording portion (“L” portion) of the“L-H” recording film is set to 18%, and the upper limit value γ is setto 32%; and the lower limit value δ of the light reflection factor ofthe non-recording portion (“H” portion) of the “H-L” recording film isset to 40%, and the upper limit value ε is set to 85%.

FIGS. 23 and 24 show reflection factors at a non-recording position anda recorded position in a variety of recording films in the presentembodiment. In the case where an H format has been employed (refer to“Chapter 7: Description of H Format”), an optical reflection factorrange at the non-recording portion is specified as shown in FIG. 22,whereby a signal appears in a same direction in an emboss area (such assystem leas-in area SYLDI) and a recording mark area (data lead-in areaDTLDI, data lead-out area DTLDO, or data area DTA) in the “L-H”recording film while a groove level is defined as a reference.Similarly, in the “H-L” recording film, while a groove level is definedas a reference, a signal appears in an opposite direction in an embossarea (such as system lead-in area SYSDI) and a recording mark area (datalead-in area DTLDI, data lead-out area DTLDO, or data area DTA).Utilizing this phenomenon, a detecting circuit design corresponding tothe “L-H” recording film and “H-L” recording film is facilitated inaddition to use for recording film identification between the “L-H”recording film and the “H-L” recording film. In addition, thereproduction signal characteristics obtained from a recording markrecorded on the “L-H” recording film shown in the present embodiment isadjusted to conform to signal characteristics obtained from the “H-L”recording film to meet formulas (20) to (23). In this manner, in thecase of using either one of the “L-H” recording film and the “H-L”recording film, the same signal processor circuit can be used, and thesignal processor circuit can be simplified and reduced in price.

Referring to FIGS. 90A, 90B, 91A, 91B, and 92, a description will begiven with respect to another embodiment relevant to an embodimentshowing a relationship in light reflection factor between an “H-L”recording film and an “L-H” recording film shown in FIGS. 22 to 24.

In the present embodiment, as shown in FIGS. 8B and 8C, the width Wg ofthe pre-groove area 11 is set to be wider than the width Wl of the landarea 12. In this manner, as shown in FIG. 90B, according to the presentembodiment, a signal level (Iot)groove from the pre-groove area 11 isincreased when tracking is carried out on the pre-groove area 11 (datalead-in area DTLDI or data area DTA and inside of data lead-out areaDTLDO).

Referring to FIG. 90A, a description will be given with respect to adetection signal (and its signal detecting circuit) in the presentembodiment. A laser light beam 1117 emitted from a semiconductor laser1121 is produced as a parallel light beam through a collimator lens1122. Then, the produced light beam passes through a beam splitter 1123,and then, the split light beam is focused onto a pre-groove area 1111 ofan information recording medium 1101 by means of an objective lens 1128.The light beam reflected in the pre-groove area 1111 of the informationrecording medium 1101 is reflected again by means of the beam splitter1123 after it has passed through the objective lens 1128, and thereflected light beam is irradiated onto an optical detector 1125 througha focusing lens 1124. The optical detector 1125 has an optical detectingcell 1125-1 and an optical detecting cell 1125-2. An I1 signal isdetected from the optical detecting cell 1125-1, and an I2 signal isdetected from the optical detecting cell 1125-2.

FIG. 82A describes a structure of another example of an optical headwhich exists in the information recording/reproducing section 141 shownin FIG. 11. As shown in FIG. 82A, the laser light beam emitted from asemiconductor laser 1021 is produced as a parallel light beam by meansof a collimator lens 1122; the produced light beam is focused by meansof an objective lens 1028 via a beam splitter 1023; and the focusedlight beam is irradiated into a pre-groove area 1011 of an informationrecording medium 1001. The pre-groove area 1011 includes a fine wobble.The light beam reflected from the wobbled pre-groove area 1011 passesthrough the objective lens 1028 again; the resulting light beam isreflected by means of the beam splitter 1023; and the reflected lightbeam is irradiated to an optical detector 1025 by means of a focusinglens 1024.

The optical detector 1025 is composed of an optical detecting cell 1025a and an optical detecting cell 1025 b. A difference between signals I1and I2 detected from the respective optical detecting cells 1025 a and1025 b is obtained, and the obtained signal is input to the wobblesignal detecting section 135 shown in FIG. 11. The optical head shown inFIG. 82A can detect both of the wobble signal and a track shiftdetection signal in a push-pull system.

In the detection signal (and its detecting circuit) shown in FIG. 82B, adifference between I1 and I2 is taken, and a track shift detectionsignal is obtained. However, in a detection signal (and its signaldetecting circuit) shown in FIG. 90A, the signals I1 and I2 are added toeach other by means of an adder 1126, and an (I1+I2) signal is detected.FIG. 90B shows a signal waveform detected by the signal (I1+I2). FIG.90B shows a detection signal level of a reproduction signal when a focusspot caused by the objective lens 1128 of the optical head shown in FIG.90A has been irradiated to each area on the information storage medium1101. As shown in FIG. 35C, in a write-once type information storagemedium according to the present embodiment, the inside of a systemlead-in area SYLDI is produced as an emboss pit area 211, and embosspits are formed everywhere. Thus, in the system lead-in area SYLSI, areproduction signal is obtained from the emboss pits as shown in FIG.90B. Here, the highest detection signal level in the system lead-in areaSYLDI is defined as I11HP.

In the present embodiment, a “light reflection factor” is defined byusing a detection signal level detected by using an optical head, asdescribed below.

First, a parallel laser light beam of an incident light quantity I_(o)is irradiated to a specific area free from fine irregularities such aspre-pits or pre-grooves of the information storage medium 1101; areflection light quantity I_(R) of the parallel laser light beamreflected from the information storage medium 1101 is measured; and avalue of Rs=I_(R)/I_(o) is utilized as a reference of the lightreflection factor Rs. In this way, the value measured without using anoptical head is defined as a calibrated light reflection factor Rs.Next, a detection signal level detected by using an optical head in itspredetermined area is defined as reflection light power Ds, and a valueof (Rs/Ds) is utilized as a conversion coefficient for converting into a“light reflection factor” from the detection signal level detected byusing the optical head at each position of the information storagemedium 1101. That is, when the above predetermined area has beenreproduced on the optical head shown in FIG. 90A, a detection signallevel output from the adder 1126 is measured as the reflection lightpower Ds. For example, an optical head moves into the system lead-inarea SYLDI; the highest detection signal level I11HP is measured fromamong the detection signal levels of the adder 1126 obtained therein;and a value of (Rs/Ds)×I11HP is defined as I11HP which is a reflectionfactor in the system lead-in area SYLDI.

According to the present embodiment, a reflection factor of aninformation recording medium is specified so that the light reflectionfactor of the system lead-in area SYLDI of the “H-L” recording filmranges from 16% to 32%. As shown in FIG. 35C, there exists a connectionarea CNA formed on a mirror surface 210 adjacent to the system lead-inarea SYLDI formed in the emboss pit area 211. The light reflectionfactor when focus spot focused by means of the objective lens 1128 ofthe optical head shown in FIG. 90A has moved to the connection area CNAis obtained as a uniform detection signal level everywhere because ofthe absence of a emboss pit. In addition, there exists a data lead-inarea DTLDI adjacent to the connection area CNA, and there existpre-grooves in pre-groove areas 214 (FIG. 35C) of the data lead-in areaDTLDI, a data area DTA, and a data lead-out area DTLDO. On each of thesepre-groove areas 214, a detection signal level when a track loop ON hasbeen applied is produced as a level of (Iot)groove shown in FIG. 90B. Inthe case where a recording mark has been formed on this pre-groove, alight reflection quantity is reduced in location of the recording markin the “H-L” recording film. Thus, as shown in FIG. 90B, a detectionsignal level of the recording film is lower than the level of(Iot)groove. The highest detection signal level in the area in which therecording mark has been recorded is defined as I11HM. The lightreflection factor in this groove area 214 is also defined by(Rs/Ds)×I11HM as described previously. The light reflection factor inlocation in which the recording mark is formed in the “H-L” recordingfilm according to the present embodiment is specified in the range of14% to 28%. Further, a ratio (Iot)groove/I11HP of the light reflectionquantity (Iot)groove in a unrecorded area in the “H-L” recording film tothe reflection factor I11HP in the system lead-in area SYLDI accordingto the present embodiment is specified at a high level so as to beincluded in the range of 0.5 to 1.0. As shown in FIGS. 8B and 8C, thewidth Wg of the pre-groove area 11 is narrower than the width Wl of theland area 12, thereby increasing a level of (Iot)groove as shown in FIG.90B. In particular, in the “H-L” recording film, as shown in FIGS. 8Band 8C, thickness Dg of the recording layer 3-2 is increased, therebyreducing a step difference quantity Hr between groove and land areas. Inthis manner, the level of (Iot)groove is increased so that a value of(Iot)groove/I11HP is 50% or more. As a result, the light reflectionquantity I11HM from the recording mark recorded in the groove area 11can be increased, and the detection signal amplitude from the recordingmark on the groove area 11 is increased.

Now, referring to FIGS. 91A and 91B, a description will be given withrespect to a detection signal level in an “L-H” recording film. Anoptical head structure and a detection signal (signal detecting methodand detecting circuit) shown in FIG. 91A are completely identical tothose shown in FIG. 90A. The light reflection quantity in the systemlead-in area SYLDI of the “L-H” recording film is defined by(Rs/Ds)×I11HP as in the “H-L” recording film. In the present embodiment,the light reflection factor in the system lead-in area SYLDI of the“L-H” recording film is specified in the range of 14% to 28%. In the“L-H” recording film, the thicknesses Dg and Dl of the recording film3-2 in the pre-groove area 11 and the land area 12 shown in FIGS. 8B and8C are relatively made small. Thus, the detection signal level(Iot)groove in an unrecorded area of the pre-groove area 214 when atrack loop is ON in an unrecorded area is lower than that of the “H-L”recording film shown in FIG. 90B. As a result, in the presentembodiment, a ratio (Iot)groove/I11HP of the light reflection quantity(Iot)groove on the pre-groove area 214 at an unrecorded position of thedata lead-in area DTLDI, the data area DTA, or the data lead-out areaDTLDO is set to be lower than that of the “H-L” recording film so as tobe included in the range of 40% to 80%. In the “L-H” recording film, thelight reflection factor in the recording mark increases moresignificantly than the reflection factor of the unrecorded area, andthus, a reproduction signal waveform as shown in FIG. 91B is produced.In FIG. 91B as well, the highest detection signal level I11HM of thereproduction signal from the recording mark is used as the lightreflection quantity, and the reflection factor is specified by(Rs/Ds)×I11HM. In the present embodiment, the reflection factor in the“L-H” recording film ranges from 14% to 28%.

FIG. 92 collectively shows the detection signal levels in the “L-H”recording film and “H-L” recording film shown in FIGS. 90B and 91B.

According to the present embodiment, the light reflection range in thesystem lead-in area SYLDI is specified so as to partially overlap in the“L-H” recording film and the “H-L” recording film. There exists anoverlap portion a of the light reflection factors between the “H-L”recording film and the “L-H” recording film in the system lead-in areaSYLDI shown in FIG. 92. In the present embodiment, this light reflectionrange in this area ranges from 16% to 28%. The present embodiment uses amethod for overlapping the reflection factor range between the “H-L”recording film and the “L-H” recording film in this system lead-in areaSYLDI in which an overlap portion of the reflection factors between the“H-L” recording film and the “L-H” recording film in the system lead-inarea SYLDI is produced by controlling optical characteristics of eachrecording layer 3-2. Further, as shown in FIG. 92, there is provided anoverlap portion β of the light reflection factor range when a track loopis ON in the data lead-in area DTLDI, the data DTA, or the data lead-outarea DTLDO. In this overlap portion, as shown in FIG. 90B, the(Iot)groove level in an unrecorded area of the “H-L” recording film isset to be higher than a signal level of the detection signal level(Iot)groove in an unrecorded area of the “L-H” recording film shown inFIG. 91B, whereby the overlap portion β between the light reflectionfactors exists. Specifically, as shown in FIGS. 8B and 8C, the filmthicknesses Dg and Dl of the recording layer 3-2 are set to be greaterin the “H-L” recording film than in the “L-H” recording film. As aresult, a step difference Hr in the light reflection layer 4-2 of the“H-L” recording film is smaller than that of the “L-H” recording film.As a result, the detection signal level (Iot)groove in an unrecordedarea of the “H-L” recording film increases. In the present embodiment,as shown in FIG. 92, the light reflection factor range when a track loopis ON is coincident between the “H-L” recording film and the “L-H”recording film. In addition, the overlap portion β of the lightreflection factor is maximized between the “H-L” recording film and the“L-H” recording film in the data area DTA or the like. Further, in thepresent embodiment, there exists a portion γ at which the lightreflection factors overlap each other between the portion α at which thelight reflection factors in the system lead-in area SYLDI overlap eachother and the portion β at which the light reflection factors in thedata area DTA overlap each other. In the informationrecording/reproducing apparatus or information reproducing apparatusaccording to the present embodiment, as shown in FIG. 13 or 15, areproduction signal in the system lead-in area SYLDI and a reproductionsignal in the data area DTA are detected by using the same preamplifiercircuit 304. A maximum value level of a detection signal can be stablydetected by means of the preamplifier 304 in the case where the lightreflection factor ranges from 5% to 50%. Therefore, all the lightreflection factors are set in the range of 5% to 50% in accordance withthe characteristics of the preamplifier 304. As a result, onepreamplifier can be commonly used for signal detections in the systemlead-in area SYLDI and in the data area DTA, thus making it possible toachieve cost reduction of the information recording/reproducingapparatus or the information recording apparatus. In the presentembodiment, as shown in FIG. 92, the portion γ at which the lightreflection factors overlap each other is increased between the portion αat which the light reflection factors in the system lead-in area SYLDIoverlap each other and the portion β at which the light reflectionfactors in the data area DTA overlap each other, thereby making itpossible to more stably detect a signal by means of the preamplifier304. In the present embodiment, as shown in FIG. 8B or 8C, the width Wgof the pre-groove area 11 is wider than the width Wl of the land area12, and a detection signal level (Iot)groove from a groove in anunrecorded area such as the inside of the data area DTA is reduced,thereby increasing the overlap portion γ of the light reflection factorsbetween the portions α and β.

Now, a description will be given below with respect to anotherembodiment of a light reflectivity in the “H-L” recording film and the“L-H” recording film shown in FIGS. 31, 35 and 24. FIG. 92 shows a lightreflectivity of another embodiment that corresponds to the embodimentshown in FIG. 31. Another embodiment that corresponds to the embodimentshown in FIG. 35 corresponds to those shown in FIGS. 90A, 90B, 91A and91B.

5-2) Characteristics of Light Absorption Spectra Relating to “L-H”Recording Film in the Present Embodiment

As has been described in “3-4) Description of characteristics relatingto “H-L” recording film in the present embodiment, the relativeabsorbance in an unrecorded area is basically low in the “H-L” recordingfilm, and thus, when reproduction light has been irradiated at the timeof reproduction, there occurs an optical characteristic change generatedby absorbing energy of the reproduction light. Even if an opticalcharacteristic change (update of recording action) has occurred afterthe energy of the reproduction light has been absorbed in a recordingmark having high absorbance, a light reflection factor from therecording mark is lowered. Thus, reproduction signal processing is lessaffected because such a change works in a direction in which anamplitude of a reproduction signal (I₁₁≡I_(11H)−I_(11L)) of thereproduction signal increases.

In contrast, the “L-H” recording film has optical characteristics that“a light reflection factor of an unrecorded portion is lower than thatin a recording mark”. This means that, as is evident from the contentsdescribed with respect to FIG. 2B, the absorbance of the unrecordedportion is higher than that in the recording mark. Thus, in the “L-H”recording film, signal degradation at the time of reproduction is likelyto occur as compared with the “H-L” recording film. As described in“3-2-B] Basic characteristics common to organic dye recording materialin the invention”, there is a need for improving reliability ofreproduction information in the case where reproduction signaldegradation has occurred due to ultraviolet ray or reproduction lightirradiation”.

As a result of checking the characteristics of an organic dye recordingmaterial in detail, it has been found that a mechanism of absorbing theenergy of reproduction light to cause an optical characteristic changeis substantially analogous to that of an optical characteristic changedue to ultraviolet ray irradiation. As a result, if there is provided astructure of improving durability relevant to ultraviolet rayirradiation in an unrecorded area, signal degradation at the time ofreproduction hardly occurs. Thus, the present embodiment is featured inthat, in the “L-H” recording film, a value of λ_(max) write (maximumabsorption wavelength which is the closest to wavelength of recordinglight) is longer than a wavelength of recording light or reproductionlight (close to 405 nm). In this manner, the absorbance relevant to theultraviolet ray can be reduced, and the durability relevant toultraviolet ray irradiation can be significantly improved. As is evidentfrom FIG. 26, a difference in absorbance between a recorded portion andan unrecorded portion in the vicinity of λ_(max) write is small, and adegree of reproduction signal modulation (signal amplitude) in the casewhere the wavelength light in the vicinity of λ_(max) write is reduced.In view of a wavelength change of a semiconductor laser light source, itis desirable that a sufficiently large degree of reproduction signalmodulation (signal amplitude) be taken in the range of 355 nm to 455 nm.Therefore, in the present embodiment, a design of a recording film 3-2is made so that a wavelength of λ_(max) write exists out of the range of355 nm to 455 nm (i.e., at a longer wavelength than 455 nm).

FIG. 25 shows an example of light absorption spectra in the “L-H”recording film in the present embodiment. As described in “5-1)Description of feature relating to “L-H” recording film, a lower limitvalue β of a light reflection factor at a non-recording portion (“L”section) of the “L-H” recording film is set to 18%, and an upper limitvalue γ is set to 32% in the present embodiment. From 1−0.32=0.68, inorder to meet the above condition, it is possible to intuitivelyunderstand whether or not a value Al₄₀₅ of the absorbance in anunrecorded area at 405 nm should meet:Al₄₀₅≧68%   (36)

Although the light reflection factor at 405 nm of the light reflectionlayer 4-2 in FIGS. 2A and 2B is slightly lowered than 100%, it isassumed that the factor is almost close to 100% for the sake ofsimplification. Therefore, the light reflection factor when absorbanceAl=0 is almost 100%. In FIG. 25, the light reflection factor of thewhole recording film at a wavelength of λ_(max) write is designated byRλ_(max) write At this time, assuming that the light reflection factoris zero (Rλ_(max) write≈0), formula (36) is derived. However, inactuality, the factor is not set to “0”, and thus, it is necessary todrive a severer formula. A severe conditional formula for setting theupper light value γ of the light reflection factor of the non-recordingportion ‘“L” portion) of the “L-H” recording film to 32% is given by:1−Al ₄₀₅×(1−Rλ _(max) write)≦0.32   (37)

In a conventional write-once type information storage medium, only the“H-L” recording film is used, and there is no accumulation ofinformation relating to the “L-H” recording film. However, in the caseof using the present embodiment described later in “5-3) Anion portion:azo metal complex+cation portion: dye” and “5-4) Using “copper” as azometal complex+center metal”, the most severest condition which meetsformula (37) is obtained as:Al₄₀₅≧80%   (38)

In the case of using an organic dye recording material described laterin the embodiment, when an optical design of a recording film is madeincluding a margin such as a characteristic variation at the time ofmanufacture or a thickness change of the recording layer 3-2, it hasbeen found that a minimum condition which meet the reflection factordescribed in the section “Description of feature relating to “L-H”recording film” in the present embodiment:Al₄₀₅≧40%   (39)may be met. Further, by meeting either of:Al₃₅₅≧40%   (40)Al₄₅₅≧40%   (41)it is possible to ensure stable recording characteristics orreproduction characteristics even if a wavelength of a light source ischanged in the range of 355 nm to 405 nm or in the range of 405 nm to455 nm (in the range of 355 nm to 455 nm in the case where both of theformulas are met at the same time).

FIG. 26 shows a light absorption spectrum change after recorded in the“L-H” recording film according to the present embodiment. It isconsidered that a value of a maximum absorption wavelength λI_(max) in arecording mark deviates from a wavelength of λ_(max) write, and aninter-molecular array change (for example, an array change between azometal complexes) occurs. Further, it is considered that a discoloringaction (cutting of local electron orbit (local molecular linkdissociation)) occurs in parallel to a location in which both of theabsorbance in location of λl_(max) and the absorbance Al₄₀₅ at 405 nmare lowered and the light absorption spectra spreads itself.

In the “L-H” recording film according to the present embodiment as well,by meeting each of formulas (20), (21), (22), and (23), the same signalprocessor circuit is made available for both of the “L-H” recording filmand the “H-L” recording film, thereby promoting simplification and pricereduction of the signal processor circuit. In formula (20), when:I ₁₁ /I _(11H)≡(I _(11H) −I _(11L))/I _(11H)≧0.4   (42),is modified,I _(11H) ≧I _(11L)/0.6   (43)is obtained. As described previously, in the present embodiment, a lowerlimit value β of a light reflection factor of an unrecorded portion (“L”portion) of an “L-H” recording film is set to 18%, and this valuecorresponds to I_(11L). Further, conceptually, the above valuecorresponds to:I _(11H)≅≈1−Ah ₄₀₅×(1−Rλ _(max write))   (44).

Thus, from formulas (43) and (44), the following formula is established:1−Ah ₄₀₅×(1−Rλ _(max write))≧0.18/0.6   (45)

In comparison between the above formulas (46) and (36), it is found thatthe values of Al₄₀₅ and Ah₄₀₅ may be seemingly set in the vicinity of68% to 70% as values of absorbance. Further, in view of a case in whichthe value of Al₄₀₅ is obtained in the range of formula (39) andperformance stability of a signal processor circuit, a sever conditionis obtained as:Ah₄₀₅≦0.4   (47)

If possible, it is desirable to meet;Ah₄₀₅≦0.3   (48)

5-3) Anion Portion: Azo Metal Complex+Cation Portion: Dye

A description will be specifically given with respect to an organic dyematerial in the present embodiment having characteristics described in“5-1) Description of characteristics relating to “L-H” recording film inthe present embodiment”, the present embodiment meeting a conditionshown in “5-2) Characteristics of optical absorption spectra relating to“L-H” recording film” in the present embodiment”. The thickness of therecording layer 3-2 meets the conditions shown in formulas (3), (4),(27), and (28), and is formed by spinner coating (spin coating). Forcomparison, a description will be given by way of example. A crystal ofa “salt” is assembled by “ion coupling” between positively charged“sodium ions” and negatively charged “chloride ions”. Similarly, inpolymers as well, there is a case in which a plurality of polymers arecombined with each other in the form close to “ion coupling”, formingconfiguring an organic dye material. The organic dye recording film 3-2in the present embodiment is composed of a positively charged “cationportion” and a negatively charged “anion portion”. In particular, theabove recording film is technically featured in that: coupling stabilityis improved by utilizing a “dye” having chromogenic characteristics forthe positively charged “cation portion” and utilizing an organic metalcomplex for the negatively charged “anion portion”; and there is met acondition that “δ] an electron structure in a chromogenic area isstabilized, and structural decomposition relevant to ultraviolet ray orreproduction light irradiation hardly occurs” shown in “3-2-B] Basicfeature common to organic dye recording material in the presentembodiment”. Specifically, in the present embodiment, an “azo metalcomplex” whose general structural formula is shown in FIG. 3 is utilizedas an organic metal complex. In the present embodiment which comprises acombination of an anion portion and a cation portion, cobalt or nickelis used as a center metal M of this azo metal complex, thereby enhancingoptical stability. There may be used: scandium, yttrium, titanium,zirconium, hafnium, vanadium, niobium, tantalum, chrome, molybdenum,tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium,rhodium, iridium, palladium, platinum, copper, silver, gold, zinc,cadmium, or mercury and the like without being limited thereto.

In the present embodiment, as a dye used for the cation portion, thereis used any of a cyanine dye whose general structural formula is shownin FIG. 27; a styril dye whose general structural formula is shown inFIG. 28; and a monomethine cyanine dye whose general structural formulais shown in FIG. 29.

Although an azo metal complex is used for the anion portion in thepresent embodiment, a formazane metal complex whose general structuralformula is shown in FIG. 30 may be used without being limited thereto,for example. The organic dye recording material comprising the anionportion and cation portion is first powdered. In the case of forming therecording layer 3-2, the powdered organic dye recoding material isdissolved in organic solvent, and spin coating is carried out on thetransparent substrate 2-2. At this time, the organic solvent to be usedincludes: a fluorine alcohol based TFP (tetrafluoro propanol) orpentane; hexane; cyclohexane; petroleum ether; ether or analogous,nitrile or analogous, and any of a nitro compound or sulfur-containingcompound or a combination thereof.

Chapter 6: Description Relating to Pre-Groove Shape/Pre-Pit Shape inCoating Type Organic Dye Recording Film and on Light Reflection LayerInterface

6-1) Light Reflection Layer

As described in “Chapter 0: Description of Relationship between UseWavelength and the Present Embodiment”, the present embodiment assumes arange of 355 nm to 455 nm in particular around 405 nm. When the metalmaterials each having a high light reflection factor at this wavelengthbandwidth are arranged in order from the highest light reflectionfactor, Ag is in the order of around 96%; Al is in the order of around80%, and Rh is in the order of around 80%. In a write-one typeinformation storage medium using an organic dye recording material, asshown in FIG. 2B, the reflection light from the light reflection layer4-2 is a standard, and thus, the light reflection layer 4-2 requires ahigh light reflection factor in characteristics. In particular, in thecase of the “H-L” recording film according to the present embodiment,the light reflection factor in an unrecorded area is low. Thus, if thelight reflection factor in the light reflection layer 4-2 simplex islow, in particular, a reproduction signal C/N ratio from a pre-pit(emboss) area is low, lacking the stability at the time of reproduction.Thus, in particular, it is mandatory that the light reflection factor inthe light reflection layer 4-2 simplex is high. Therefore, in thepresent embodiment, in the above wavelength bandwidth, a material mainlymade of Ag (silver) having the highest reflection factor is used. As amaterial for the light reflection layer 4-2, there occurs a problem that“atoms easily move” or “corrosion easily occurs” if silver is usedalone. To solve the first problem, when partial alloying is carried outby adding other atoms, silver atoms hardly move. In the first embodimentin which other atoms are added, the light reflection layer 4-2 is madeof AgNdCu according to the first embodiment. AgNdCu is in a solidsoluble state, and thus, the reflection factor is slightly lowered thana state in which silver is used alone. In the second embodiment in whichother atoms are added, the light reflection layer 4-2 is made of AgPd,and an electric potential is changed, whereby corrosion hardly occurs inan electrochemical manner. If the light reflection layer 4-2 corrodesdue to silver oxidization or the like, the light reflection factor islowered. In an organic dye recording film having a recording filmstructure shown in FIG. 2B, in particular, in the case of an organic dyerecording film shown in “Chapter 3: Description of Characteristics ofOrganic Dye Recording Film in the Present Embodiment”, in particular, alight reflection factor on an interface between the recording layer 3-2and the light reflection later 4-2 is very important. If correctionoccurs on this interface, the light reflection factor is lowered, and anoptical interface shape blurs. In addition, the detection signalcharacteristics from a track shift detection signal (push-pull signal)or a wobble signal and a pre-pit (emboss) area are degraded. Inaddition, in the case where the width Wg of the pre-groove area 11 iswider than the width Wi of the land area, a track shift detection signal(push-pull signal) or a wobble signal is hardly generated, thusincreasing effect of degradation of the light reflection factor on theinterface between the recording layer 3-2 and the light reflection layer4-2 due to corrosion. In order to prevent degradation of the lightreflection factor on this interface, AgBi is used for the lightreflection layer 4-2 as the third embodiment. AgBi forms a very stablephase and prevents degradation of the light reflection factor on theabove interface because a passive coat film is formed on a surface(interface between the recording layer 3-2 and the light reflectionlayer 4-2). That is, if Bi (bismuth) is slightly added to Ag, Bi isisolated from the above interface, the isolated Bi is oxidized. Then, avery fine film (passive coat film) called oxidized bismuth is formed tofunction to preclude internal oxidization. This passive coat film isformed on the interface, and forms a very stable phase. Thus, thedegradation of a light reflection factor does not occur, and thestability of detection signal characteristics from a track shiftdetection signal (push-pull signal) or a wobble signal and a pre-pit(emboss) area is guaranteed over a long period of time. At a wavelengthband ranging from 355 nm to 455 nm, the silver simplex has the highestlight reflection factor, and the light reflection factor is lowered asan additive amount of other atoms is increased. Thus, it is desirablethat an additive amount of Bi atoms in AgBi in the present embodiment beequal to or smaller than 5 at %. The unit of at % used here denotesatomic percent, and indicates that five Bi atoms exist in a total atomnumber 100 of AgBi, for example. When characteristics have beenevaluated by actually producing the passive coat film, it has found thata passive coat film can be produced as long as an additive amount of Biatoms is equal to or greater than 0.5 at %. Based on a result of thisevaluation, an additive amount of Bi atoms in the light reflection layer4-2 in the present embodiment is defined as 1 at %. In this thirdembodiment, only one atom Bi is added, and an additive amount of atomscan be reduced as compared with AgNdCu according to the first embodiment(a case in which two types of atoms Nd and Cu is added in Ag), and AgBican increase the light reflection factor more significantly than AgNdCu.As a result, even in the case of the “H-L” recording film according tothe present embodiment or in the case where the width Wg of thepre-groove area 11 is wider than the with Wl of the land area, as shownin FIGS. 8B and 8C, a detection signal can be stably obtained from atrack shift detection signal (push-pull signal) or a wobble signal and apre-pit (emboss) area with high precision. The third embodiment is notlimited to AgBi, and a ternary system including AgMg, AgNi, AgGa, AgNx,AgCo, AgAl or the atoms described previously may be used as a silverallow which produces a passive coat film. The thickness of this lightreflection layer 4-2 is set in the range of 5 nm to 200 nm. If thethickness is smaller than 5 nm, the light reflection layer 4-2 is notuniform, and is formed in a land shape. Therefore, the thickness of thelight reflection layer 4-2 is set to 5 nm. When an AgBi film is equal toor smaller than 80 nm in thickness, the film permeates to its back side.Thus, in the case of a one-sided single recording layer, the thicknessis set in the range of 80 nm to 200 nm, and preferably, in the range of100 nm to 150 nm. In the case of a one-sided double recording layer, thethickness is set in the range of 5 nm to 15 nm.

6-2) Description Relating to Pre-Pit Shape in Coating Type Organic DyeRecording Film and on Light Reflection Layer Interface

In an H format according to the present embodiment, as shown in FIGS.35A, 35B and 35C, the system lead-in area SYLDI is provided. In thisarea, an emboss pit area 211 is provided, and, as shown in FIGS. 71A and71B, information is recorded in advance in the form of a pre-bit. Areproduction signal in this area is adjusted to conform to reproductionsignal characteristics from a read-only type information storage medium,and a signal processor circuit in an information reproducing apparatusor an information recording/reproducing apparatus shown in FIG. 11 iscompatible with a read-only type information storage medium and awrite-once type information storage medium. A definition relevant to asignal detected from this area is adjusted to conform with a definitionof “3-4): Description of characteristics relating to “H-L” recordingfilm in the invention”. That is, a reproduction signal amount from thespace area 14 having a sufficiently large length (11T) is defined asI_(11H), and a reproduction signal from the pre-pit (emboss) area 13having a sufficiently large length (11T) is defined as I_(11L). Inaddition, a differential value between these amounts is defined asI₁₁=I_(11H)−I_(11L). In the present embodiment, in accordance with thereproduction signal characteristics from the read-only type informationstorage medium, the reproduction signal in this area is set to be:I ₁₁ /I _(11H)≧0.3   (54)and desirably, is set to be:I ₁₁ /I _(11H)>0.5   (55)

When a repetitive signal amplitude of the space area 14 relevant to thepre-pit (emboss) area 13 having a 2t length is defined as I₂, theamplitude is set to be:I ₂ /I ₁₁≧0.5   (56)and desirably, is set to be:I ₂ /I ₁₁>0.7   (57)

A description will be given with respect to a physical condition formeeting the above formula (54) or formula (55).

As has been described in FIG. 2B, the signal characteristics from apre-pit are mainly dependent on the reflection in the light reflectionlayer 4-2. Therefore, the reproduction signal amplitude value I₁₁ isdetermined depending on a step amount Hpr between the space area 14 andthe pre-pit (emboss) area 13 in the light reflection layer 4-2. Whenoptical approximation calculation is made, this step amount Hpr, withrespect to a reproduction light wavelength λ and a refractive index n₃₂in the recording layer 3-2, has the following relationship:I ₁₁∝ sin²{(2π×Hpr×n ₃₂)/λ  (58)

From formula (58), it is found that I₁₁ becomes maximal whenHpr≅λ/(4×n₃₂). In order to meet formula (54) or formula (55), fromformula (58), it is necessary to meet:Hpr≧λ/(12×n ₃₂)   (59)and desirably,Hpr>λ/(6×n ₃₂)   (60)

As described in “Chapter 0: Description of Relationship between UseWavelength and the Present Embodiment”, λ=355 nm to 455 nm is used inthe embodiment, and as described in “2-1) Difference in Principle ofRecording/Recording Film and Difference in Basic Concept Relating toGeneration of Reproduction Signal”, n₃₂=1.4 to 1.9 is established. Thus,when this value is substituted into formula (59) or formula (60), a stepis produced so as to meet a condition:Hpr≧15.6 nm   (62)and desirably,Hpr>31.1 nm   (63)

In the conventional write-once type information storage medium, as shownin FIG. 71B, the thickness of the recording layer 3-2 is small in thespace area 14, and thus, a step on an interface between the lightreflection layer 4-2 and the recording layer 3-2 is small, and formula(62) has not successfully met. In contrast, in the present embodiment, acontrivance has been made to ensure that a relationship between thethickness Dg of the recording layer 3-2 in the pre-pit (emboss) area 13and the thickness Dl of the recording layer 3-2 in the space area 14conform with a condition described in “3-2-E] Basic characteristicsrelating to thickness distribution of recording layer in the presentembodiment for definition of parameters”. As a result, as shown in FIG.71B, a sufficiently large step Hpr which meets formula (62) or formula(63) has been successfully provided.

By carrying out optical approximation discussion as described above, inthe present embodiment, in order to have sufficient resolution of areproduction signal so as to meet formula (56) or formula (57), acontrivance is made so that the width Wp of the pre-pit (emboss) area 13is equal to or smaller than half of track pitches as shown in FIG. 71B,and a reproduction signal from the pre-pit (emboss) area 13 can belargely taken.

Chapter 7: Description of H Format

Now, an H format in the present embodiment will be described here.

FIG. 31 shows a structure and dimensions of an information storagemedium in the present embodiment. As embodiments, there are explicitlyshown three types of embodiments of information storage mediums such as:

“read-only type information storage medium” used exclusively forreproduction in which recording cannot be carried out;

“write-once type information storage medium” capable of additionalrecording; and

“rewritable type information storage medium” capable of rewriting orrecording any times

As shown in FIG. 31, the above three types of information storagemediums are common to each other in a majority of structure anddimensions. In all of the three types of information storage mediums,from their inner periphery side, a burst cutting area BCA, a systemlead-in area SYLDI, a connection area CNA, a data lead-in area DTLSI,and a data area DTA have been arranged. All the mediums other than anOPT type read-only medium is featured in that a data lead-out area DTLDOis arranged at the outer periphery. As described later, in the OPT typeread-only medium, a middle area MDA is arranged at the outer periphery.In either of the write-once type and rewritable type mediums, the insideof this area is for read-only (additional writing disabled). In theread-only type information storage medium, information is recorded inthe data lead-in area DTLDI in the form of emboss (pre-pit). Incontrast, in the write-once type and the rewritable type informationstorage medium, new information can be additionally written (rewrittenin the rewritable type) by forming a recording mark in the data lead-inarea DTLDI. As described later, in the write-once type and rewritabletype information storage medium, in the data lead-out area DTLDO, therecoexist an area in which additional writing can be carried out(rewriting can be carried out in the rewritable type) and a read-onlyarea in which information is recorded in the form of emboss (pre-pit).As described previously, in the data area DTA, data lead-in area DTLVI,data lead-out area DTSDO, and middle area MDA shown in FIG. 31, highdensity of the information storage medium is achieved (in particular,line density is improved) by using a PRML (Partial Response MaximumLikelihood) method for reproduction of signals recorded therein. Inaddition, in the system lead-in area SYLDI and the system lead-out areaSYLDO, compatibility with a current DVD is realized and the stability ofreproduction is improved by using a slice level detecting system forreproduction of signals recorded therein.

Unlike the current DVD specification, in the embodiment shown in FIG.31, the burst cutting area BCA and system lead-in area SYLDI areseparated from each other in location without being superimposed on eachother. These areas are physically separated from each other, therebymaking it possible to prevent interference between the informationrecorded in the system lead-in area SYLDI at the time of informationreproduction and the information recorded in the burst cutting area BCAand to allocate information reproduction with high precision.

Now, a description will be given with respect to internal signalcharacteristics and data structure of a burst cutting area BCA shown inFIG. 31. At the time of measuring a BCA signal, a focusing spot of laserlight beams emitted from an optical head needs to be focused on arecording layer. A reproduction signal obtained in the following burstcutting area BCA is filtered by means of a secondary low-pass vesselfilter for a shutdown frequency of 550 kHz. The following signalcharacteristics of the burst cutting area BCA are defined in the rangeof 22.4 mm to 23.0 mm in radius from the center in the informationstorage medium. With respect to a reproduction signal from the burstcutting area BCA, the waveform shown in FIG. 102A is obtained; themaximum and minimum levels when a BCA code and a channel bit are set to“0” are defined as IBHmax and IBHmin; and the maximum bottom level ofthe BCA code and a channel bit “1” is defined as IBLmax. In addition, anintermediate level is defined as (IBHmin+IBLmax)/2.

In the present embodiment, detection signal characteristics are definedunder a condition that (IBLmax/IBHmin) is 0.8 or less and under acondition that (IBHmax/IBHmin) is 1.4 or less. A cyclic signal of theBCA code and channel bit is shown in FIG. 102B. While an average levelbetween IBL and IBH is defined as a reference, a position at which theBCA signal crosses the reference position is regarded as an edgeposition. The cycle of the BCA signal is defined when a rotation speedis 2760 rpm (46.0 Hz). As shown in FIG. 102B, a cycle between thefront-end edges (the falling positions) is defined as 4.63×n±1.00 μs,and a width of a pulse position in location in which an amount of lightis lowered (an interval from a first fall position to a next fallposition) is defined as 1.56±0.75 μs.

The BCA code is often recorded after manufacture of an informationstorage medium has been terminated. However, in the case where thesignal characteristics reproduced from the BCA code satisfy those shownin FIGS. 102A and 102B, the BCA code may be recorded in advance as apre-pit. The BCA code is recorded in a direction along the circumferenceof the information storage medium. This BCA code is also recorded sothat a direction in which a pulse width narrows coincides with adirection in which a light reflectivity is lowered. The BCA code isrecorded after modulated in accordance with an RZ modulating method. Apulse having a narrow pulse width (=having a low reflectivity) needs tobe narrower than half of a channel clock width of the thus modulated BCAcode.

FIG. 103 shows a BCA data structure. BCA data contains two BCA preambles73 and 74, two post-ambles 76 and 77, and two BCA data areas BCAA. A BCAerror detection code EDC_(BCA) and a BCA error correction code ECC_(BCA)are added to each of the BCA data areas BCAA, and a BCA link area 75 isallocated therebetween. Further, a sync byte SB_(BCA) or re-syncRS_(BCA) for each byte is inserted on a four by four byte basis. Theforegoing BCA preambles 73 and 74 each are composed of 4 bytes, and allsettings “00h” are recorded. In addition, the sync byte SB_(BCA) isallocated immediately preceding each of the BCA preambles 73 and 74. 76bytes are set in the BCA data area BCAA. The BCA post-ambles 76 and 77each are composed of 4 bytes, and a repetition pattern of all settings“55h” is recorded. The BCA ink area 75 is composed of 4 bytes, and allsettings “AAh” are repeatedly recorded. FIG. 104 shows bit patterns ofthe BCA sync byte SB_(BCA) and BCA re-sync RS_(BCA). Two types of mode Aand mode B exist as bit patterns. In the case of mode A, a fixed pattern67 is produced. In the case of mode B, a sync code 68 is obtained.

FIGS. 105A to 105G each show an example of the contents of the BCAinformation recorded in a BCA data area. The BCA data area BCAA iscapable of recording 76-type information, and data is recorded in unitsof BCA record units BCAU. The information recorded in this BCA recordunit internal BCAU is referred to as a BCA record. The size of each BCArecord is produced as an integer multiple of 4 bytes. In each of the BCArecords, as shown in FIG. 105C, there are sequentially recorded: BCArecord ID 61 composed of 2 bytes; version number information 62 composedof 1 byte; data length information 63 on recording data composed of 1byte; and a data record (recording data 64) of 4m bytes. The IDs to beset in BCA record ID 61 are assigned in the range of 0000h to 7FFFFh inaccordance with a publicly acceptable utilizing method, and from 8000hto FFFFh are assigned in accordance with an individual utilizing method.The version number information 62 composed of 1 byte is divided intomajor number 71 of the significant 4 bits and minor number 72 of theleast significant 4 bits. The first integer digit of version number isrecorded in major number 71, and a value of a first digit after thedecimal point of version number is recorded in minor number 72. Forexample, in the case of version “2.4”, number “2” is recorded in thefield of major number 71, and number “4” is recorded in the field ofminor number 72.

In the H format according to the present embodiment, identificationinformation 80 on an HD DVD standard type is recorded in the BCA record,as shown in FIG. 105E. Specifically, with respect to the contents ofthis information, as shown in FIG. 105F, there are recorded: BCA recordID 81; version number information 82; and data length information 83 onrecording data. In addition, there are recorded: standard typeinformation 84 composed of 4 bits; disc type information 85 composed of4 bits; extended part version information 86 (1 byte); and a reservedarea 87 (2 bytes). Recording mark polarity (identification of H-L orL-H) information 88 is allocated in the significant 1 bit in the disctype information 85, and the remaining 3 bits are assigned to a reservedarea 89.

The following configuration can be provided as another example of thedata structure shown in FIGS. 105A to 105G. That is, the BCA recordrecorded in the BCA record unit BCAU #1 (8 bytes) shown in FIG. 105B cancontain the following items of information in the following order:

1) “BCA Record ID” of 2 bytes that is an HD DVD book type identifier;

2) “Version number” of 1 byte indicating a version number;

3) “Data length” of 1 byte indicating a data length;

4) “Book type and Disc type” of 1 byte indicating a book type and a disctype;

5) “Extended Part version” of 1 byte indicating an extended portionversion; and

6) Reserved 2 bytes.

Here, “Disc type” included in the above “Book type and Disc type” isconfigured so that “Mark polarity” and “Twin format flag” can bedescribed. The “Mark polarity” described in this “Disc type” is providedas information that corresponds to the “recording mark polarityinformation 88” described previously. When “Mark polarity=0b”, itindicates “Low-to-High disc” featured in that “a signal from a mark isgreater than a signal from a space”; and when “Mark polarity=1b”, itindicates “High-to-Low disc” featured in that “a signal from a mark issmaller than a signal from a space”.

On the other hand, “Twin format flag” described in “Disc type” isprovided as information indicating whether or not the disc is a twinformat disc. “Twin format flag=0b” indicates that the disc is not a twinformat disc, and “Twin format flag=1b” indicates that the disc is a twinformat disc. The “twin format disc” described herein is a disc featuredin that the disc has two recording/reproducing layers of differentformats (other formats defined in a DVD forum) depending onrecording/reproducing layers are applied. This “Twin format flag” isprovided as a BCA record, whereby, in individual multi-layered HD DVD-R(High Definition DVD Recordable) disc, it is possible to easilydiscriminate whether the disc is a single format disc or a multi-formatdisc.

As shown in FIG. 103, the same information as those contained in a BCAdata area BCAA surrounded by a BCA preamble 73 and a BCA post-amble 76is described in a BCA data area BCAA surrounded by a BCA preamble 74 anda BCA post-amble 77. In this manner, the same information is multiplywritten into the plurality of BCA data areas BCAA. Thus, even if oneitem of data cannot be reproduced due to an effect of dust or scratchproduced on a surface of an information storage medium, data can bereproduced from the other BCA data area BCAA. As a result, thereliability of the data recorded in the BCA data area BCAA is remarkablyimproved.

Further, in the BCA data structure shown in FIG. 103, in addition to theBCA error detection code EDC_(BCA) that exists conventionally, a BCAerror correction code ECC_(BCA) further exists. Thus, even if an erroroccurs with the data contained in the BCA data area BCAA, such an errorcan be corrected by the BCA error correction code ECC_(BCA), and thereliability is further improved.

In the case where an “L-H” type recording film has been used as anotherembodiment, there is a method for forming fine irregularities in advancein location for allocating the burst cutting area BCA. A descriptionwill be given later with respect to information on polarity(identification of “H-L” or “L-H”) of a recording mark which exists at a192nd byte in FIG. 42. In this section, a description will be given withrespect to the present embodiment in which an “L-H” recording film aswell as the “H-L” recording film is also incorporated in a specificationand a scope of selecting the recording film is widened to enable highspeed recording or supply of an inexpensive medium. As described later,the present embodiment also considers a case of using the “L-H”recording film. Data recorded in the burst cutting area BCA (barcodedata) is formed by locally carrying out laser exposure to a recordingfilm. As shown in FIGS. 35A, 35B and 35C, the system lead-in area SYLDIis formed of the emboss bit area 211, and thus, the reproduction signalfrom the system lead-in area SYLDI appears in a direction in which alight reflection amount decreases as compared with a light reflectionlevel from the mirror surface 210. If while the burst cutting area BCAis formed as the mirror surface 210, in the case where the “L-H”recording film has been used, a reproduction signal from the datarecorded in the burst cutting area BCA appears in a direction in which alight reflection amount increases more significantly than a lightreflection level from the mirror surface 210 (in an unrecorded state).As a result, a significant step occurs between a position (amplitudelevel) of a maximum level and a minimum level of the reproduction signalfrom the data recorded in the burst cutting area BCA and a position(amplitude level) of a maximum level and a minimum level of thereproduction signal from the system lead-in area SYLDI. As describedlater with respect to FIGS. 35A, 35B and 35C, an information reproducingapparatus or an information recording/reproducing apparatus carry outprocessing in accordance with the steps of:

1) reproducing information in the burst cutting area BCA;

2) reproducing information contained in a information data zone CDZ inthe system lead-in area SYLDI;

3) reproducing information contained in the data lead-in area DTLDI (inthe case of write-once type or rewriting type);

4) readjusting (optimizing) a reproduction circuit constant in areference code recording zone RCZ; and

5) reproducing information recorded in the data area DTA or recordingnew information.

Thus, if there exists a large step between a reproduction signalamplitude level from the data formed in the burst cutting area BCA and areproduction signal amplitude level from the system lead-in area SYLDI,there occurs a problem that the reliability of information reproductionis lowered. In order to solve this problem, in the case where the “L-H”recording film is used as a recording film, the present embodiment isfeatured in that fine irregularities are formed in advance in thus burstcutting area BCA. When such fine irregularities are formed, the lightreflection level becomes lower than that from the mirror surface 210 dueto a light interference effect at the stage prior to recording data(barcode data) by local laser exposure. Then, there is attained anadvantageous effect that a step is remarkably decreased between areproduction signal amplitude level (detection level) from the dataformed in the burst cutting area BCA and a reproduction signal amplitudelevel (detection level) from the system lead-in area SYLDI; thereliability of information reproduction is improved; and processinggoing from the above item (1) to item (2) is facilitated.

In the case of using the “L-H” recording film, the specific contents offine irregularities formed in advance in the burst cutting area BCAinclude the emboss pit area 211 like the system lead-in area SYLDI.Another embodiment includes a method for forming the groove area 214 orthe land area and the groove area 213 like the data lead-in area DTLDIor data area DTA. As has been described in the description ofembodiments in which the system lead-in area SYSDI and burst cuttingarea BCA are separately arranged, if the burst cutting area BCA and theemboss bit area 211 overlaps each other, there increases a noisecomponent from the data provided in the burst cutting area BCA due tounnecessary interference to a reproduction signal.

When the groove area 214 or the land area and groove area 213 is formedwithout forming the emboss pit area 211 as an embodiment of the fineirregularities in the burst cutting area BCA, there is attained anadvantageous effect that there decreases a noise component from the dataformed in the burst cutting area BCA due to unnecessary interference toa reproduction signal and the quality of a reproduction signal isimproved.

When track pitches of the groove area 214 or the land area and groovearea 213 formed in the burst cutting area BCA are adjusted to conformwith the those of the system lead-in area SYLDI, there is attained anadvantageous effect that the manufacturing performance of theinformation storage medium is improved. That is, at the time of originalmaster manufacturing of the information storage medium, emboss pits inthe system lead-in area are produced while a feed motor speed is madeconstant. At this time, the track pitches of the groove area 214 or theland area and groove area 213 formed in the burst cutting area BCA areadjusted to conform with those of the emboss pits in the system lead-inarea SYLDI, thereby making it possible to continuously maintain aconstant motor speed in the burst cutting area BCA and the systemlead-in area SYLDI. Thus, there is no need for changing the speed of thefeed motor midway, and thus, the pitch non-uniformity hardly occurs, andthe manufacturing performance of the information storage medium isimproved.

FIG. 32 shows parameter values according to the present embodiment in aread-only type information storage medium; FIG. 33 shows parametervalues according to the present embodiment in a write-once typeinformation storage medium; and FIG. 34 shows parameter values accordingto the present embodiment in a rewritable type information storagemedium. As is evident in comparison between FIG. 32 or 33 and FIG. 34(in particular, in comparison of section (B)), the rewritable typeinformation storage medium has higher recording capacity than theread-only type or write-once type information storage medium bynarrowing track pitches and line density (data bit length). As describedlater, in the rewritable type information storage medium, the trackpitches are narrowed by reducing effect of a cross-talk of the adjacenttracks by employing land-groove recording. Alternatively, any of theread-only type information storage medium, write-once informationstorage medium, and rewritable-type information storage medium isfeatured in that the data bit length and track pitches (corresponding torecording density) of the system lead-in/system lead-out areasSYLDI/SYLDO are greater than those of the data lead-in/data lead-outarea DTLDI/DTLDO (in that the recording density is low).

The data bit length and track pitches of the system lead-in/systemlead-out areas SYLDI/SYLDO are close to the values of the current DVDlead-in area, thereby realizing compatibility with the current DVD.

In the present embodiment as well, like the current DVD-R, an embossstep in the system lead-in/system lead-out areas SYLDI/SYLDO of thewrite-once type information storage medium is shallowly defined. In thismanner, there is attained advantageous effect that a depth of apre-groove of the write-once information storage medium is shallowlydefined and a degree of modulation of a reproduction signal from arecording mark formed on a pre-groove by additional writing isincreased. In contrast, as a counteraction against it, there occurs aproblem that the degree of modulation of the reproduction signal fromthe system lead-in/system lead-out areas SYLDI/SYLDO decreases. In orderto solve this problem, the data bit length (and track pitches) of systemlead-in/system lead-out areas SYLDI/SYLDO are roughened and a repetitionfrequency of pits and spaces at the narrowest position is isolated(significantly reduced) from an optical shutdown frequency of an MTF(Modulation Transfer Function) of a reproduction objective lens, therebymaking it possible to increase the reproduction signal amplitude fromthe system lead-in/system lead-out areas SYLDI/SYLDO and to stabilizereproduction.

FIGS. 35A, 35B and 35C show a comparison of detailed data structure in asystem lead-in area SYLDI and a data lead-in area DTLDI in a variety ofinformation storage mediums. FIG. 35A shows a data structure of aread-only type information storage medium; FIG. 35B shows a datastructure of a rewritable-type information storage medium; and FIG. 35Cshows a data structure of a write-once type information storage medium.

As shown in FIG. 35A, except that only a connection zone CNZ is formedas a mirror surface 210, the read-only type information storage mediumis featured in that the emboss pit area 211 having emboss pits formedtherein is provided in all of the system lead-in area SYLDI and datalead-in area DTLDI and data area DTA. The emboss pit area 211 isprovided in the system lead-in area SYLDI, and the connection zone CNZis provided in the mirror surface 210. As shown in FIG. 35B, therewritable-type information storage medium is featured in that the landarea and the groove area 213 are formed in the data lead-in area DTLSIand the data area DTA. The write-once type information storage medium isfeatured in that the groove area 214 is formed in the data lead-in areaDTLDI and the data area DTA. Information is recorded by forming arecording mark in the land area and the groove area 213 or groove area214.

The initial zone INZ indicates a start position of the system lead-inarea SYLDI. As significant information recorded in the initial zone INZ,there is discretely arranged data ID (Identification Data) informationincluding information on physical sector numbers or logical sectornumbers described previously. As described later, one physical sectorrecords information on a data frame structure composed of data ID, IED(ID Error Detection code), main data for recording user information, andEDO (Error detection code); and the initial zone records information onthe above described data frame structure. However, in the initial zoneINZ, all the information on the main data for recording the userinformation is all set to “00h”, and thus, the significant informationcontained in the initial zone INZ is only data ID information. A currentlocation can be recognized from the information on physical sectornumbers or logical sector numbers recorded therein. That is, when aninformation recording/reproducing unit 141 shown in FIG. 11 startsinformation reproduction from an information storage medium, in the casewhere reproduction has been started from the information contained inthe initial zone INZ, first, the information on physical sector numbersor logical sector numbers recorded in the data ID information issampled, and the sampled information is moved to the control data zoneCDZ while the current location in the information storage medium ischecked.

A buffer zone 1 BFZ1 and a buffer zone 2 BFZ2 each are composed of 32ECC blocks. As shown in FIGS. 32, 33 and 34, one FCC block correspondsto 1024 physical sectors. In the buffer zone 1 BFZ1 and the buffer zone2 BFZ2 as well, like the initial zone INZ, main data information is setto all “00h”.

The connection zone CNZ which exists in a CNA (Connection Area) is anarea for physically separating the system lead-in area SYLDI and thedata lead-in area DTLDI from each other. This area is provided as amirror surface on which no emboss pit or pre-groove exists.

An RCZ (Reference code zone) of the read-only type information storagemedium and the write-once type information storage medium each is anarea used for reproduction circuit tuning of a reproducing apparatus(for automatic adjustment of tap coefficient values at the time ofadaptive equalization carried out in the tap controller 332 shown inFIG. 15), wherein information on the data frame structure describedpreviously is recorded. A length of the reference code is one ECC block(=32 sectors). The present embodiment is featured in that the RCZ(Reference code zone) of the read-only type information storage mediumand the write-once information storage medium each is arranged adjacentto a DTA (data area). In any of the structures of the current DVD-ROMdisc and the current DVD-R disc as well, a control data zone is arrangedbetween the reference code zone and data area, and the reference codezone and the data area are separated from each other. If the referencecode zone and data area are separated from each other, a tilt amount ora light reflection factor of the information storage medium or therecording sensitivity of a recording film (in the case of the write-onceinformation storage medium) slightly changes. Therefore, there occurs aproblem that an optimal circuit constant in the data area is distortedeven if a circuit constant of the reproducing apparatus is adjusted. Inorder to solve the above described problem, when the RCZ (reference codezone) is arranged adjacent to the DTA (data area), in the case where thecircuit constant of the information reproducing apparatus has beenoptimized in the RCZ (reference code zone), an optimized state ismaintained by the same circuit constant in the DTA (data area). In thecase where an attempt is made to precisely reproduce a signal inarbitrary location in the DTA (data area), it becomes possible toreproduce a signal at a target position very precisely in accordancewith the steps of:

1) optimizing a circuit constant of the information reproducingapparatus in the RCZ (reference code zone);

2) optimizing a circuit constant of the information reproducingapparatus again while reproducing a portion which is the closest to thereference code zone RCZ in the data area DTA;

3) optimizing a circuit constant once again while reproducinginformation at an intermediate position between a target position in thedata area DTA and the position optimized in step (2); and

4) reproducing signal after moving to the target position.

GTZ1 and GTZ2 (guard track zones 1 and 2) existing in the write-onceinformation storage medium and the rewritable-type information storagemedium are areas for specifying the start boundary position of the datalead-in area DTLDI, and a boundary position of a drive test zone DRTZand a disc test zone DKTZ. These areas are prohibited from beingrecorded a recording mark. The guard track zone 1 GTZ1 and guard trackzone 2 GTZ2 exist in the data lead-in area DTLDI, and thus, in thisarea, the write-once type information storage medium is featured in thatthe pre-groove area is formed in advance. Alternatively, therewritable-type information storage medium is featured in that thegroove area and the land area are formed in advance. In the pre-groovearea or groove area and the land area, as shown in FIGS. 32, 33 and 34,wobble addresses are recorded in advance, and thus, the current locationin the information storage medium is determined by using these wobbleaddresses.

The disc test zone DKTZ is an area provided for manufactures ofinformation storage mediums to carry out quality test (evaluation).

The drive test zone DRTZ is provided as an area for carrying out testwriting before the information recording/reproducing apparatus recordsinformation in the information storage medium. The informationrecording/reproducing apparatus carries out test writing in advance inthis area, and identifies an optimal recording condition (writestrategy). Then, the information contained in the data area DTA can berecorded under the optimal recording condition.

The information recorded in the disc identification zone DIZ whichexists in the rewritable-type information storage medium (FIG. 35B) isan optional information recording area, the area being adopted toadditionally write a set of drive descriptions composed of: informationon manufacturer name of recording/reproducing apparatuses; additionalinformation relating thereto; and an area in which recording can beuniquely carried out by the manufacturers.

A defect management area 1 DMA1 and a defect management area 2 DMA2which exist in a rewritable-type information storage medium (FIG. 35B)record defect management information contained in the data area DTA,and, for example, substitute site information when a defect occurs orthe like is recorded.

In the write-once type information storage medium (FIG. 35C), thereexist uniquely: an RMD duplication zone RDZ; a recording management zoneRMZ; and an R physical information zone R-PFIZ. The recording managementzone RMZ records RMD (recording management data) which is an item ofmanagement information relating to a recording position of data updatedby additional writing of data. A detailed description will be givenlater. As described later in FIGS. 36A, 36B, 36C, and 36D, in thepresent embodiment, a recording management zone RMZ is set for eachbordered area BRDA, enabling area extension of the recording managementzone RMZ. As a result, even if the required recording management dataRMD increases due to an increase of additional writing frequency, suchan increase can be handled by extending the recording management zoneRMZ in series, and thus, there is attained advantageous effect that theadditional writing count can be significantly increased. In this case,in the present embodiment, the recording management zone RMZ is arrangedin a border-in BRDI which corresponds to each bordered area BRDA(arranged immediately before each bordered area BRDA). In the presentembodiment, the border-in BRDI corresponding to the first bordered areaBRDA#1 and a data lead-in area DTLDI are made compatible with eachother, and efficient use of the data area DTA is promoted while theforming of the first border-in BRDI in the data area DTA is eliminated.That is, the recording management zone RMZ in the data lead-in area DTAshown in FIG. 35C is utilized as a recording location of the recordingmanagement data RDM which corresponds to the first bordered area BRDA#1.

The RMD duplication zone RDZ is a location for recording information onthe recording management data RMD which meets the following condition inthe recording management zone RMZ, and the reliability of the recordingmanagement data RMD is improved by providing the recording managementdata RMD in a duplicate manner, as in the present embodiment. That is,in the case where the recording management data RMD contained in therecording management zone RMZ is valid due to dust or scratch adheringto a write-once information storage medium surface, the recordingmanagement data RMD is reproduced, the data being recorded in this RMDduplication zone RDZ. Further, the remaining required information isacquired by tracing, whereby information on the latest recordingmanagement data RMD can be restored.

This RMD duplication zone records recording management data RDM at atime point at which (a plurality of) borders are closed. As describedlater, a new recording management zone RMZ is defined every time oneborder is closed and a next new bordered area is set. Thus, every time anew recording management zone RMZ is created, the last recordingmanagement data RMD relating to the preceding bordered area may berecorded in this RMD duplication zone PDZ. When the same information isrecorded in this RMD duplication zone RDZ every time the recordingmanagement data RDM is additionally recorded on a write-once informationstorage medium, the RMD duplication zone RDZ becomes full with acomparatively small additional recording count, and thus, an upper limitvalue of the additional writing count becomes small. In contrast, as inthe present embodiment, in the case where a recording management zone isnewly produced when a border is closed, the recording management zone inthe border-in BRDI becomes full, and a new recording management zone RMZis formed by using an R zone, there is attained advantageous effect thatonly the last recording management data RMD contained in the pastrecording management zone RMZ is recorded in the RMD duplication zoneRDZ, thereby making it possible to improve an allowable additionalwriting count by efficiently using the RMD duplication zone RDZ.

For example, in the case where the recording management data RMDcontained in the recording management zone RMZ which corresponds to thebordered area BRDA on the way of additional writing (before closed)cannot be reproduced due to the dust or scratch adhering to the surfaceof the write-once type information storage medium, a location of thebordered area BRDA, which has been already closed, can be identified byreading the recording management data RMD lastly recorded in this RMDduplication zone RDZ. Therefore, the location of the bordered area BRDAon the way of additional writing (before closed) and the contents ofinformation recorded therein can be acquired by tracing another locationin the data area DTA of the information storage medium, and theinformation on the latest recording management data RMD can be restored.

An R physical information zone R-PFIZ records the information analogousto the physical format PFI contained in the control data zone CDZ whichexists common to FIGS. 35A to 35C (described later in detail).

FIG. 36C shows a data structure in the RMD duplication zone RDZ and therecording management zone RMZ which exists in the write-once typeinformation storage medium. FIG. 36A shows the same structure as thatshown in FIG. 35C, and FIG. 36B shows an enlarged view of the RMDduplication zone RDZ and the recording management zone RDZ shown in FIG.35C. As described above, in the recording management zone RMZ containedin the data lead-in area DTLDI, data relating to recording managementwhich corresponds to the first bordered area BRDA is collectivelyrecorded, respectively, in one items of recording management data (RMD);and new recording management data RMD is sequentially additionallywritten at the back side every time the contents of the recordingmanagement data RMD generated when additional writing process has beencarried out in the write-once information storage medium are updated.That is, the RMD (Recording Management Data) is recorded in size unitsof single physical segment block (a physical segment block will bedescribed later), and new recording management data RMD is sequentiallyadditionally written every time the contents of data are updated. In theexample shown in FIG. 36B, a change has occurred with management data inlocation recording management data RMD#1 and RMD#2 has been recorded.Thus, this figure shows an example in which the data after changed(after updated) has been recorded as recording management data RMD#3immediately after the recording management data RMD#2. Therefore, in therecording management zone RMD, a reserved area 273 exists so thatadditional writing can be further carried out.

Although FIG. 36B shows a structure in the recording management zone RMZwhich exists in the data lead-in area DTLDI, a structure in therecording management zone RMZ (or extended recording management zone:referred to as extended RMZ) which exists in the border-in BRDI orbordered area BRDA described later is also identical to the structureshown in FIG. 36B without being limited thereto.

In the present embodiment, in the case where a first bordered areaBRDA#l is closed or in the case where the terminating process(finalizing) of the data area DTA is carried out, a processing operationfor padding all the reserved area 273 shown in FIG. 36B with the latestrecording management data RMD duplication zone is carried out. In thismanner, the following advantageous effects are attained:

1) An “unrecorded” reserved area 273 is eliminated, and thestabilization of tracking correction due to a DPD (Differential PhaseDetection) technique is guaranteed;

2) the latest recording management data RMD is overwritten in the pastreserved area 273, thereby remarkably improving the reliability at thetime of reproduction relating to the last recording management data RMD;and

3) an event that different items of recording management data RMD aremistakenly recorded in an unrecorded reserved area 273 can be prevented.

The above processing method is not limited to the recording managementzone RMZ contained in the data lead-in area DTLDI. In the presentembodiment, with respect to the recording management zone RMZ (orextended recording management zone: referred to as extended RMZ) whichexists in the border-in BRDI or bordered area BRDA described later, inthe case where the corresponding bordered area BRDA is closed or in thecase where the terminating process (finalizing) of the data area DTA iscarried out, a processing operation for padding all the reserved area273 shown in FIG. 36B with the latest recording management data RMD iscarried out.

The RMD duplication zone RDZ is divided into the RDZ lead-in area RDZLIand a recording area 271 of the last recording management data RMDduplication zone RDZ of the corresponding RMZ. The RDZ lead-in areaRDZLI is composed of a system reserved field SRSF whose data size is 48KB and a unique ID field UIDF whose data size is 16 KB, as shown in FIG.36B. All “00h” are set in the system reserved field SRSF.

The present embodiment is featured in that DRZ lead-in area RDZLI isrecorded in the data lead-in area DTLDI which can be additionallywritten. In the write-once type information storage medium according tothe present embodiment, the medium is shipped with the RDZ lead-in areaRDZLI being in an unrecorded state immediately after manufacturing. Inthe user's information recording/reproducing apparatus, at a stage ofusing this write-once type information storage medium, RDZ lead-in areaRDZLI information is recorded. Therefore, it is determined whether ornot information is recorded in this RDZ lead-in area RDZLI immediatelyafter the write-once type information storage medium has been mounted onthe information recording/reproducing apparatus, thereby making itpossible to easily know whether or not the target write-once typeinformation storage medium is in a state immediately aftermanufacturing/shipment or has been used at least once. Further, as shownin FIGS. 36A to 36D, the present embodiment is secondarily featured inthat the RMD duplication zone RDZ is provided at the inner peripheryside than the recording management zone RMZ which corresponds to a firstbordered area BRDA, and the RDZ lead-in RDZLI is arranged in the RMDduplication zone RDZ.

The use efficiency of information acquisition is improved by arranginginformation (RDZ lead-in area RDZLI) representing whether or not thewrite-once type information storage medium is in a state immediatelyafter manufacturing/shipment or has been used at least once in the RMDduplication zone RDZ used for the purpose of a common use (improvementof reliability of RMD). In addition, the RDZ lead-in area RDZLI isarranged at the inner periphery side than the recording management zoneRMZ, thereby making it possible to reduce a time required foracquisition of required information. When the information storage mediumis mounted on the information recording/reproducing apparatus, theinformation recording/reproducing apparatus starts reproduction from theburst cutting area BCA arranged at the innermost periphery side, asdescribed in FIG. 31, and sequentially changes a reproducing locationfrom the system lead-in SYLSI to the data lead-in area DTLDI while thereproduction position is sequentially moved to the innermost peripheryside. It is determined whether or not information has been recorded inthe RDZ lead-in area RDZLI contained in the RMD duplication zone RDZ. Ina write-once type information storage medium in which no recording iscarried out immediately after shipment, no recording management data RMDis recorded in the recording management zone RMZ. Thus, in the casewhere no information is recorded in the RDZ lead-in area RDZLI, it isdetermined that the medium is “unused immediately after shipment”, andthe reproduction of the recording management zone RMD can be eliminated,and a time required for acquisition of required information can bereduced.

As shown in FIG. 36C, a unique ID area UIDF records information relatingto an information recording/reproducing apparatus for which thewrite-once type information storage medium immediately after shipmenthas been first used (i.e., for which recording has been first started).That is, this area records a drive manufacturer ID 281 of theinformation recording/reproducing apparatus or serial number 283 andmodel number 284 of the information recording/reproducing apparatus. Theunique ID area UIDF repeatedly records the same information for 2 KB(strictly, 2048 bytes) shown in FIG. 36C. Information contained in theunique disc ID 287 records year information 293, month information 294,date information 295, time information 296, minutes information 297, andseconds information 298 when the storage medium has been first used(recording has been first started). A data type of respective items ofinformation is described in HEX, BIN, ASCII as described in FIG. 36D,and two types or four bytes are used.

The present embodiment is featured in that the size of an area of thisRDZ lead-in area RDZLI and the size of the one recording management dataRMD are 64 KB, i.e., the user data size in one ECC block becomes aninteger multiple. In the case of the write-once type information storagemedium, it is impossible to carry out a processing operation forrewriting ECC block data after changed in the information storage mediumafter changing part of the data contained in one ECC block. Therefore,in particular, in the case of the write-once type information storagemedium, as described later, data is recorded in recording cluster unitscomposed of an integer multiple of a data segment including one ECCblock. Therefore, the size of the area of the RDZ lead-in area RDZLI andthe size of such one item of recording management data RMD are differentfrom a user data size in an ECC block, there is a need for a paddingarea or a stuffing area for making adjustment to the recording clusterunit, and a substantial recording efficiency is lowered. As in thepresent embodiment, the size of the area of the RDZ lead-in area RDZLIand the size of such one item of recording management data RMD are setto an integer multiple of 64 KB, thereby making it possible to lower therecording efficiency.

A description will be given with respect to a last recording managementdata RMD recording area 271 of the corresponding RMZ shown in FIG. 36B.As described in Japanese Patent No. 2621459, there is a method forrecording intermediate information at the time of interruption ofrecording inwardly of the lead-in area. In this case, every timerecording is interrupted or every time an additional writing process iscarried out, it is necessary to serially additionally write intermediateinformation in this area (recording management data RMD in the presentembodiment). Thus, if such recording interruption or additional writingprocess is frequently repeated, there is a problem that this areabecomes full immediately and a further adding process cannot be carriedout. In order to solve this problem, the present embodiment is featuredin that an RMD duplication zone RDZ is set as an area capable ofrecording the recording management data RMD updated only when a specificcondition is met and the recording management data RMD sampled undersuch a specific condition is recorded. Thus, there is attainedadvantageous effect that the RMD duplication zone RDZ can be preventedfrom being full and the numbers of additional writings enable withrespect to the write-once type information storage medium can beremarkably improved by lowering the frequency of the recordingmanagement data RMD additionally written in the RMD duplication zoneRDZ. In parallel to this effect, the recording management data updatedevery time an additional writing process is carried out is seriallyadditionally written in the recording management zone RMZ in theborder-in area BRDI shown in FIG. 36A (in the data lead-in area DTLDI asshown in FIG. 36A with respect to the first bordered area BRDA#1) or therecording management zone RMZ utilizing an R zone described later. Whena new recording management zone RMZ is created, for example, when thenext bordered area BRDA is created (new border-in area BRDI is set) orwhen a new recording management zone RMZ is set in an R zone, the lastrecording management data RMD (the newest RMD in a state immediatelybefore creating a new recording management zone RMZ) is recorded in (thecorresponding last recording management data RMD recording area 271)contained in the RMD duplication zone RDZ. In this manner, there isattained advantageous effect that a newest RMD position search isfacilitated by utilizing this area in addition to a significantlyincrease of additional writing enable count for the write-once typeinformation storage medium.

FIGS. 38A to 38C show a data structure in the recording management dataRMD shown in FIGS. 36A to 36D. FIGS. 38A to 38C show the same contentsof FIGS. 36A to 38C. As described previously, in the present embodiment,the border-in area BRDI for the first bordered area BRDA#1 is partiallycompatible with the data lead-in area DTLDI, and thus, the recordingmanagement data RMD#1 to #3 corresponding to the first bordered area arerecorded in the recording management zone RMZ in the data lead-in areaDTLDI. In the case where no data is recorded in the data area DTA, theinside recording management zone RMZ is provided as a reserved area 273in which all data is in an unrecorded state. The recording managementdata RMD updated every time data is additionally written in the dataarea DTA is recorded in first location contained in this reserved area273, and the corresponding recording management data RMD is sequentiallyadditionally written in the first bordered area contained in therecording management zone RMZ. The size of the recording management dataRMD additionally written each time in the recording management zone RMZis defined as 64 KB. In the present embodiment, one ECC block iscomposed of 64 KB data, and thus, an additional writing process issimplified by adjusting the data size of this recording management dataRMD to conform with one ECC block size. As described later, in thepresent embodiment, one data segment 490 is configured by adding part ofa guard area before and after one ECC block data 412, and recordingclusters 540 and 542 in units of additional writing or rewriting areconfigured by adding extended guard fields 258 and 259 to one or more(n) data segments. In the case of recording the recording managementdata RMD, the recording clusters 540 and 542 including only one datasegment (one ECC block) are sequentially additionally written in thisrecording management zone RMZ. As described later, a length of alocation for recording one data segment 531 corresponds to that of onephysical segment block composed of seven physical segments 550 to 556.

FIG. 38C shows a data structure in one recording management data RMF#1.FIG. 38C shows a data structure in recording management data RMD#1contained in the data lead-in area DTLDI. The illustrated data structureis identical to a data structure in the recording management data RMD#Aand #B (FIG. 36B) recorded in the RMD duplication zone RDZ; (extended)recording management data RMD recorded in a border-in area BRDIdescribed later; (extended) recording management data RMD recorded in anR zone; and copy CRMD of RMD recorded in the border-out area BRDO (FIG.39D) as well. As shown in FIG. 38C, one item of recording managementdata RMD is composed of a reserved area and RMD fields ranging from “0”to “21”. In the present embodiment, 32 physical sectors are included inone ECC block composed of 64 KB user data, and user data of 2 KB(strictly, 2048 bytes) is recorded in one physical sector. Each RMDfield are assigned by 2048 bytes in conformance to a user data sizerecorded in this physical sector, and relative physical sector numbersare set. RMD fields are recorded on a write-once type informationstorage medium in order of these relative physical sector numbers. Thecontents of data recorded in each RMD field are as follows:

RMD field 0 . . . Information relating to disc state and data areaallocation (information relating to location for allocating a variety ofdata in data area)

RMD field 1 . . . Information relating to used test zone and informationrelating to recommended recording waveform

RMD field 2 . . . User available area

RMD field 3 . . . Start position information on border area andinformation relating to extended RMZ position

RMD fields 4 to 21 . . . Information relating to position of R zone

As shown in FIGS. 35A to 35C in any of the read-only type, write-oncetype, and rewritable-type information storage medium, the presentembodiment is featured in that a system lead-in area is arranged at anopposite side of a data area while a data lead-in area is sandwichedbetween the two areas, and further, as shown in FIG. 31, the burstcutting area BCA and the data lead-in area DTLDI are arranged at anopposite side to each other while the system lead-in area SYSDI issandwiched between the two areas. When an information storage medium isinserted into the information reproducing apparatus or informationrecording/reproducing apparatus shown in FIG. 11, the informationreproducing apparatus or information recording/reproducing apparatuscarries out processing in accordance with the steps of:

1) reproducing information contained in the burst cutting area BCA;

2) reproducing information contained in the information data zone CDZcontained in the system lead-in area SYLDI;

3) reproducing information contained in the data lead-in area DTLDI (inthe case of a write-once type or a rewritable-type medium);

4) readjusting (optimizing) a reproduction circuit constant in thereference code zone RCZ; and

5) reproducing information recorded in the data area DTA or recordingnew information.

As shown in FIGS. 35A to 35C, information is sequentially arranged fromthe inner periphery side along the above processing steps, and thus, aprocess for providing an access to an unnecessary inner periphery iseliminated, the number of accesses is reduced, and the data area DTA canbe accessed. Thus, there is attained advantageous effect that a starttime for reproducing the information recording in the data area orrecording new information is accelerated. In addition, RPML is used forsignal reproduction in the data lead-in area DTDLI and data area DTA byutilizing a slice level detecting system for signal reproduction in thesystem lead-in area SYLDI. Thus, if the data lead-in area DTLDI and thedata area DTA are made adjacent to each other, in the case wherereproduction is carried out sequentially from the inner periphery side,a signal can be stably reproduced continuously merely by switching aslice level detecting circuit to a PRML detector circuit only oncebetween the system lead-in area SYLDI and the data lead-in area DTLDI.Thus, the number of reproduction circuit switchings along thereproduction procedures is small, thus simplifying processing controland accelerating a data intra-area reproduction start time.

FIGS. 37A to 37F show a comparison of the data structures in the dataareas DTA and the data lead-out areas DTLDO in a variety of informationstorage mediums. FIG. 37A shows a data structure of a read-only typeinformation storage medium; FIGS. 37B and 37C each show a data structureof a writing-type information storage medium; and FIGS. 37D to 37F eachshow a data structure of a write-once type information storage medium.In particular, FIGS. 37B and 37D each show a data structure at the timeof an initial state (before recording); and FIGS. 37C, 37E and 37F eachshow a data structure in a state in which recording (additional writingor rewriting) has advanced to a certain extent.

As shown in FIG. 37A, in the read-only type information storage medium,the data recorded in the data lead-out area DTLDO and the systemlead-out area SYLDO each have a data frame structure (described later indetail) in the same manner as in the buffer zone 1 BFZ1 and buffer zone2 BFZ2 shown in FIGS. 35A to 35C, and all values of the main datacontained therein are set to “00h”. In the read-only type informationstorage medium, a user data prerecording area 201 can be fully used inthe data area DTA. However, as described later, in any of theembodiments of the write-once information storage medium andrewritable-type information storage medium as well, userrewriting/additional writing enable ranges 202 to 205 are narrower thanthe data area DTA.

In the write-once information storage medium or rewritable-typeinformation storage medium, an SPA (Spare Area) is provided at theinnermost periphery of the data area DTA. In the case where a defect hasoccurred in the data area DTA, a substituting process is carried out byusing the spare area SPA. In the case of the rewritable-type informationstorage medium, the substitution history information (defect managementinformation) is recorded in a defect management area 1 (DMA1) and adefect management area 2 (DMA2) shown in FIG. 35B; and a detectmanagement area 3 (DMA3) and a defect management area 4 (DMA4) shown inFIGS. 37B and 37C. The defect management information recorded in thedefect management area 3 (DMA3) and defect management area 4 (DMA4)shown in FIGS. 37B and 37C are recorded as the same contents of thedefect management information recorded in the defect managementinformation 1 (DMA1) and defect management information 2 (DMA2) shown inFIG. 35B. In the case of the write-once type information storage medium,substitution history information (defect management information) in thecase where the substituting process has been carried out is recorded inthe data lead-in area DTLDI shown in FIG. 35C and copy information C_RMZon the contents of recoding in a recording management zone which existsin a border zone. Although defect management has not been carried out ina current DVD-R disc, DVD-R discs partially having a defect location arecommercially available as the manufacture number of DVD-R discsincreases, and there is a growing need for improving the reliability ofinformation recorded in a write-once type information storage medium.

In the embodiment shown in FIGS. 37A to 37F, a spare area SPA is setwith respect to the write-once information storage medium, enablingdefect management by a substituting process. In this manner, a defectmanagement process is carried out with respect to the write-once typeinformation storage medium partially having a defect location, therebymaking it possible to improve the reliability of information. In therewritable-type information storage medium or write-once typeinformation storage medium, in the case where a defect frequently hasoccurred, a user judges an information recording/reproducing apparatus,and an ESPA, ESPA1, and ESPA2 (Expanded Spare Areas) are automaticallyset with respect to a state immediately after selling to the user shownin FIGS. 37A and 37D so as to widen a substitute location. In thismanner, the extended spare areas ESPA, ESPA1, and ESPA2 can be set,thereby making it possible to sell mediums with which a plenty ofdefects occur for a manufacturing reason. As a result, the manufactureyield of mediums is improved, making it possible to reduce a medialprice. As shown in FIGS. 37A, 37E and 37F, when the extended spare areasESPA, ESPA1, and ESPA2 are extended in the data area DTA, user datarewriting or additional writing enable ranges 203 and 205 decrease(s),thus making it necessary to management its associated positionalinformation. In the rewritable-type information storage medium, theinformation is recorded in the defect management area 1 (DMA1) to thedefect management area 4 (DMA4) and in the control data zone CDZ, asdescribed later. In the case of the write-once type information storagemedium, as described later, the information is recorded in recordingmanagement zones RMZ which exist in the data lead-in area DTLDI and inthe border-out BRDO. As described later, the information is recorded inthe RMD (Recording Management Data) contained in the recordingmanagement zone RMZ. The recording management data RMD is updated oradditionally written in the recoding management zone RMZ every time thecontents of management data are updated. Thus, even if an extended sparearea is reset many times, timely updating and management can be carriedout. (The embodiment shown in FIG. 37E indicates a state in which anextended spare area 2 (ESPA2) has been set because further areasubstituting setting is required due to a number of defects even afterthe extended spare area 1 (ESPA1) has been fully used).

A guard track zone 3 (GTZ3) shown in FIGS. 37B and 37C each is arrangedto separate a defect management area 4 (DMA4) and a drive test zone(DRTS) from each other, and a guard track zone 4 (GTZ4) is arranged toseparate a disc test zone DKTZ and a servo calibration zone SCZ fromeach other. The guard track zone 3 (GTZ3) and guard track zone 4 (GTZ4)are specified as area which inhibits recording by forming a recordingmark, as in the guard track zone 1 (GTZ1) and guard track zone 2 (GTZ2)shown in FIGS. 35A to 35C. The guard track zone 3 (GTZ3) and the guardtrack zone 4 (GTZ4) exist in the data lead-out area DTLDO. Thus, inthese areas, in the write-once type information storage medium, apre-groove area is formed in advance, or alternatively, in therewritable-type information storage medium, a groove area and a landarea are formed in advance. As shown in FIGS. 32 to 34, wobble addressesare recorded in advance in the pre-groove area or the groove area andland area, thus judging a current position in the information storagemedium by using this wobble addresses.

As in FIGS. 35A to 35C, a drive test zone DRTZ is arranged as an areafor test writing before an information recording/reproducing apparatusrecords information in an information storage medium. The informationrecording/reproducing apparatus carries out test writing in advance inthis area, and identifies an optimal recording condition (writestrategy). Then, this apparatus can record information in the data areaDTA under the optimal recording condition.

As shown in FIGS. 35A to 35C, the disc test zone DKTZ is an areaprovided for manufacturers of information storage mediums to carry outquality test (evaluation).

In all of the areas contained in the data lead-out area DTLDO other thanthe SCZ (Servo Calibration Zone), a pre-groove area is formed in advancein the write-once type information storage medium, or alternatively, agroove area and a land area are formed in advance in the rewritable-typeinformation storage medium, enabling recording (additional writing orrewriting) of a recording mark. As shown in FIGS. 37C and 37E, the SCZ(Servo Calibration Zone) serves as an emboss pit area 211 in the samemanner as in the system lead-in area SYLDI instead of the pre-groovearea 214 or the land area and groove area 213. This area formscontinuous tracks with emboss pits, which follows another area of thedata lead-out area DTLDO. These tracks continuously communicate witheach other in a spiral manner, and form emboss pits over 360 degreesalong the circumference of the information storage medium. This area isprovided to detect a tilt amount of the information storage medium byusing a DPD (Deferential Phase Detect) technique. If the informationstorage medium tilts, an offset occurs with a track shift detectionsignal amplitude using the DPD technique, making it possible toprecisely the tilt amount from the offset amount and a tilting directionin an offset direction. By utilizing this principle, emboss pits capableof DPD detection are formed in advance at the outermost periphery (atthe outer periphery in the data lead-out area DTLDO), thereby making itpossible to carry out detection with inexpensiveness and high precisionwithout adding special parts (for tilt detection) to an optical headwhich exists in the information recording/reproducing unit 141 shown inFIG. 11. Further, by detecting the tilt amount of the outer periphery,servo stabilization (due to tilt amount correction) can be achieved evenin the data area. In the present embodiment, the track pitches in thisservo calibration zone SCZ are adjusted to conform with another areacontained in the data lead-out area DTLD, and the manufacturingperformance of the information storage medium is improved, making itpossible to reduce a media price due to the improvement of yields. Thatis, although a pre-groove is formed in another area contained in thedata lead-out area DTLDO in the write-once type information storagemedium, a pre-groove is created while a feed motor speed of an exposuresection of an original master recording device is made constant at thetime of original master manufacturing of the write-once type informationstorage medium. At this time, the track pitches in the servo calibrationzone SCZ are adjusted to conform with another area contained in the datalead-out area DTLDO, thereby making it possible to continuously maintaina motor speed constantly in the servo calibration zone SCZ as well.Thus, the pitch non-uniformity hardly occurs, and the manufacturingperformance of the information storage medium is improved.

Another embodiment includes a method for adjusting at least either ofthe track pitches and data bit length in the servo calibration zone SCZto conform with the track pitches or data bit length of the systemlead-in area SYLDI. As described previously, the tilt amount in theservo calibration zone SCZ and its tilt direction are measured by usingthe DPD technique, and the measurement result is utilized in the dataarea DTA as well, thereby promoting servo stabilization in the data areaDTA. A method for predicting a tilt amount in the data area DTAaccording to the embodiment is featured in that the tilt amount in thesystem lead-in area SYLDI and its direction are measured in advance byusing the DPD technique similarly, and a relationship with themeasurement result in the servo calibration zone SCZ is utilized,thereby making it possible to predict the tilt amount. In the case ofusing the DPD technique, the present embodiment is featured in that theoffset amount of the detection signal amplitude relevant to a tilt ofthe information storage medium and a direction in which an offsetoccurs, change depending on the track pitches and data bit length ofemboss pits. Therefore, there is attained advantageous effect that atleast either of the track pitches and data bit length in the servocalibration zone SCZ is adjusted to conform with the track pitches ordata bit length of the system lead-in area SYLDI, whereby the detectioncharacteristics relating to the offset amount of the detection signalamplitude and the direction in which an offset occurs are madecoincident with each other depending on the servo calibration zone SCZand the system lead-in area SYLDI; a correlation between thesecharacteristics is easily obtained, and the tilt amount and direction inthe data area DTA is easily predicted.

As shown in FIGS. 35C and 37D, in the write-once type informationstorage medium, two drive test zones DRTZ are provided at the innerperiphery side and the outer periphery side of the medium. As more testwriting operations are carried out for the drive text zones DRTZ,parameters are finely assigned, thereby making it possible to search anoptimal recording condition in detail and to improve the precision ofrecording in the data area DTA. The rewritable-type information storagemedium enables reuse in the drive test zone DRTZ due to overwriting.However, if an attempt is made to enhance the recording precision byincreasing the number of test writings in the write-once typeinformation storage medium, there occurs a problem that the drive testzone is used up immediately. In order to solve this problem, the presentembodiment is featured in that an EDRTZ (Expanded Drive Test Zone) canbe set from the outer periphery to the inner periphery direction, makingit possible to extend a drive test zone. In the present embodiment,features relating to a method for setting an extended drive test zoneand a method for carrying out test writing in the set extended drivetest zone are described below.

1) The setting (framing) of extended drive test zones EDRTZ aresequentially provided collectively from the outer periphery direction(close to the data lead-out area DTLDO) to the inner periphery side.

As shown in FIG. 37E, the extended drive test zone 1 (EDRTZ1) is set asan area collected from a location which is the closest to the outerperiphery in the data area (which is the closest to the data lead-outarea DTLDO); and the extended drive test zone 1 (EDRTZ1) is used up,thereby making it possible to secondarily set the extended drive testzone 2 (EDRTZ2) as a corrected area which exists in the inner peripheryside than the current position.

2) Test writing is sequentially carried out from the inner peripheryside in the extended dive test zone EDRTZ.

In the case where test writing is carried out in the extended drive testzone EDRTZ, such test writing is carried out along a groove area 214arranged in a spiral shape from the inner periphery side to the outerperiphery side, and current test writing is carried out for anunrecorded location that immediately follows the previously test-written(recorded) location.

The data area is structured to be additionally written along the groovearea 214 arranged in a spiral manner from the inner periphery side tothe outer periphery side. A processing operation from “checkingimmediately test-written location” to “carrying out current testwriting” can be serially carried out by using a method for sequentiallycarrying out additional writing a location that follows a test writinglocation in which test writing in the extended drive test zone has beencarried out immediately before, thus facilitating a test writing processand simplifying management of the test-written location in the extendeddrive test zone EDRTZ.

3) The data lead-out area DTLDO can be reset in the form including theextended drive test zone.

FIG. 37E shows an example of setting two areas, i.e., an extended sparearea 1 (ESPA1) and an extended spare area 2 (ESPA2) in the data area DTAand setting two areas, i.e., the extended drive test zone 1 (EDRTZ1) andextended drive test zone 2 (EDRTZ2). In this case, as shown in FIG. 37F,the present embodiment is featured in that the data lead-out area DTLOcan be reset with respect to an area including up to the extended drivetest zone 2 (EDRTZ2). Concurrently, the range of data area DTA is resetin a range-narrowed manner, making it easy to manage an additionalwriting enable range 205 of the user data which exists in the data areaDTA.

In the case where the resetting has been provided as shown in FIG. 37F,a setting location of the extended spare area 1 (ESPA1) shown in FIG.37E is regarded as an “extended spare area which has already been usedup”, and an unrecorded area (area enabling additional test writing) ismanaged only in the extended spare area 2 (ESPA2) contained in theextended drive test zone EDRTZ if any. In this case, non-defectinformation which is recorded in the extended spare area 1 (ESPA1) andwhich has been used up for substitution is transferred to a location ofan area which is not substituted in the extended spare area 2 (ESPTA2),and defect management information is rewritten. The start positioninformation on the reset data lead-out area DTLDO is recorded inallocation position information on the latest (updated) data area DTA ofRMD field 0 contained in the recording management data RMD, as shown inFIG. 44.

FIGS. 100A and 100B show another embodiment of a method of setting anextended drive test zone EDRTZ shown in FIGS. 37A to 37F. The embodimentof FIGS. 100A and 100B differs from the embodiment of FIGS. 37A to 37F,as follows:

1) A guard track zone 3 GTZ3 is set between the data area DTA and thedrive test zone DRTZ shown in FIG. 37D,

2) An extended drive test zone EDRTZ is set by the size of the guardtrack zone 3 GTZ3, and the guard track zone 3 GTZ3 is shifted inparallel,

3) Since the end point of the data area DTA is shifted to the precedingdirection, the recording management data RMD indicating the end point ofthe data area DTA is additionally written in the recording positionmanagement zone RMZ.

That is, the drive test zone DRTZ is extendable. FIGS. 100A and 100Bshow an arrangement before and after an extended drive test zone is set.As shown in FIG. 100A, in the drive test zone DRTZ, test writing isperformed from the peripheral side. If there is no non-record area inthe drive test zone DRTZ, an extended drive test zone EDRTZ is set asshown in FIG. 100B, and test writing is performed from the peripheralside of the extended drive test zone EDRTZ. When the extended drive testzone EDRTZ is set, the end point of the data area DTA which can recorduser data is changed to “73183Fh” from “73543Fh”. As shown in FIG. 44,presence/absence identification information of the extended drive testzone EDRTZ is included in the arrangement location information in thelatest (updated) data area DTA. The flag of the presence\absenceidentification information is “01h” if the extended drive test zoneEDRTZ is present and “00h” if the extended drive test zone EDRTZ is notpresent. When the extended drive test zone EDRTZ is set as shown in FIG.100B, the presence\absence identification information of the extendeddrive test zone EDRTZ is changed to “01h” from “00h”. The changed(latest) recording management data RMD is additionally written in therecording position management zone RMZ after the extended drive testzone EDRTZ is set.

A structure of a border area in a write-once type information storagemedium will be described here with reference to FIGS. 40A to 40D. Whenone border area has been first set in the write-once information storagemedium, a bordered area (Bordered Area) BRDA#1 is set at the innerperiphery size (which is the closest to the data lead-in area DTLDI), asshown in FIG. 40A, and then, a border out (Border out) BRDO that followsthe above area is formed.

Further, in the case where an attempt is made to set a next borderedarea (Bordered Area) BRDA#2, as shown in FIG. 40B, a next (#1) border inarea BRDI that follows the preceding #1 border out area BRDO is formed,and then, a next bordered area BRDA#2 is set. In the case where anattempt is made to close the next bordered area BRDA#2, a (#2) borderout area BRDO that immediately follows the area BRDA#2 is formed. In thepresent embodiment, a state in which the next ((#1) border in area BRDI)that follows the preceding (#1) border out area BRDO is formed andcombined is referred to as a border zone BRDZ. The border zone BRDZ isset to prevent an optical head from overrun between the bordered areasBRDAs when reproduction has been carried out by using the informationreproducing apparatus (on the presumption that the DPD detectingtechnique is used). Therefore, in the case where a write-once typeinformation storage medium having information recorded therein isreproduced by using a read-only apparatus, it is presumed that a borderclose process is made such that the border out area BRDO and border-inarea BRDI are already recorded and the border out area BRDO that followsthe last bordered area BRDA is recorded. The first bordered area BRDA#1is composed of 4080 or more physical segment blocks, and there is a needfor the first bordered area BRDA#1 to have a width of 1.0 mm or more ina radial direction on the write-once type information storage medium.FIG. 40B shows an example of setting an extended drive test zone EDRTZin the data area DTA.

FIG. 40C shows a state obtained after finalizing a write-onceinformation storage medium. FIG. 40C shows an example in which anextended drive test zone EDRTZ is incorporated in the data lead-out areaDTLDO, and further, an extended spare area ESPA has been set. In thiscase, a user data adding enable range 205 is fully padded with the lastborder out area BRDO.

FIG. 40D shows a detailed data structure in the border zone area BRDZdescribed above. Each item of information is recorded in size units ofone physical segment blocks (physical segment block). Copy informationC_RMZ on the contents recorded in a recording management zone isrecorded at the beginning of the border out area BRDO, and a border endmark (Stop Block) STB indicating the border out area BRDOP is recorded.Further, in the case the next border in area BDI is reached, a firstmark (Next Border Marker) NBM indicating that a next border area reachesan “N1-th” physical segment block counted from a physical segment blockin which the border end mark (Stop Block) STC has been recorded; asecond mark NBM indicating that a next border region reaches an “N2-th”physical segment block; and a third mark NBM indicating that a nextborder region reaches an “N3-th” mark NBM are discretely recorded in atotal of three locations on a size by size basis of one physical segmentblock, respectively. Updated physical format information U_PFI isrecorded in the next border-in area BRDI. In a current DVD-R or a DVD-RWdisc, in the case where a next border is not reached (in the last borderout area BRDO), a location in which “a mark NBM indicating a nextborder” should be recorded (a location of one physical segment blocksize) shown in FIG. 40D is maintained as a “location in which no data isrecorded”. If border closing is carried out in this state, thiswrite-once type information storage medium (current DVD-R or DVD-RWdisc) enters a state in which reproduction can be carried out by using aconventional DVD-ROM drive or a conventional DVD player. Theconventional DVD-ROM drive or the conventional DVD player utilizes arecording mark recorded on this write-once type information storagemedium (current DVD-R or DVD-RW disc) to carry out track shift detectionusing the DPD (Differential Phase Detect) technique. However, in theabove described “location in which no data is recorded”, a recordingmark does not exist over one physical segment block size, thus making itimpossible to carry out track shift detection using the DPD(Differential Phase Detect) technique. Thus, there is a problem that atrack servo cannot be stably applied.

In order to solve the above described problem with the current DVD-R orDVD-RW disc, the present embodiment newly employed methods for:

1) in the case where a next border area is reached, recording data on aspecific pattern in advance in a “location in which the mark NBMindicating a next border should be recorded”; and

2) carrying out an “overwriting process” in a specific recording patternpartially and discretely with respect to a location indicating “the markNBM indicating a next border” in which, in the case where a next borderarea is reached, the data on the specific pattern is recorded inadvance, thereby utilizing identification information indicating that “anext border area is reached”.

By setting a mark indicating a next border due to overwriting, there isattained advantageous effect that, even in the case where a next borderarea is reached as shown in item (1), a recording mark of a specificpattern can be formed in advance in a “location in which the mark NBMindicating a next border should be recorded”, and, after border closing,even if a read-only type information reproducing apparatus carries outtrack shift detection in accordance with the DPD technique, a trackservo can be stably applied. If a new recording mark is overwrittenpartially on a portion at which a recording mark has already been formedin a write-once type information storage medium, there is a danger thatthe stability of a PLL circuit shown in FIG. 11 is degraded in aninformation recording/reproducing apparatus or an informationreproducing apparatus. In order to overcome this danger, the presentembodiment further newly employs methods for:

3) when overwriting is carried out at a position of “the mark NBMindicating a next border” of one physical segment block size, changingan overwrite state depending on a location contained in the same datasegment;

4) partially carrying out overwriting in a sync data 432 and disablingoverwriting on a sync code 431; and

5) carrying out overwriting in a location excluding data ID and IED.

As described later in detail, data fields 411 to 418 for recording userdata and guard areas 441 to 448 are alternately recorded on aninformation storage medium. A group obtained by combining the datafields 411 to 418 and the guard areas 441 to 448 is called a datasegment 490, and one data segment length coincides with one physicalsegment block length. The PLL circuit 174 shown in FIG. 11 facilitatesPLL lead-in in VFO areas 471 and 472 in particular. Therefore, even ifPLL goes out immediately before the VFO areas 471 and 472, PLLre-lead-in is easily carried out by using the VFO areas 471 and 472,thus reducing an effect on a whole system in the informationrecording/reproducing apparatus or information reproducing apparatus.There is attained advantageous effect that (3) an overwrite state ischanged depending on a location in a data segment internal location, asdescribed above, by utilizing this state, and an overwrite amount of aspecific pattern is increased at a back portion close to the VFO areas471 and 472 contained in the same data segment, thereby making itpossible to facilitate judgment of “a mark indicating a next border” andto prevent degradation of the precision of a signal PLL at the time ofreproduction.

As described in detail with respect to FIGS. 76A to 76F and FIGS. 62Aand 62B, one physical sector is composed of a combination of a locationin which sync codes (SY0 to SY3) are arranged and the sync data 434arranged between these sync codes 433. The informationrecording/reproducing apparatus or the information recording apparatussamples sync codes 43 (SY0 to SY3) from a channel bit pattern recordedon the information storage medium, and detects a boundary of the channelbit pattern. As described later, position information (physical sectornumbers or logical sector numbers) on the data recorded on theinformation storage medium is sampled from data ID information. A dataID error is sensed by using an IED arranged immediately after thesampled information. Therefore, the present embodiment enables (5)disabling overwriting on data ID and IED and (4) partially carrying outoverwriting in the sync data 432 excluding the sync code 431, therebyenabling detection of a data ID position and reproduction(content-reading) of the information recorded in data ID by using thesync code 431 in the “mark NMB indicating a next border”.

FIGS. 39A to 39D show another embodiment which is different from thatshown in FIGS. 40A to 40D relating to a structure of a border area in awrite-once type information storage medium. FIGS. 39A and 39B show thesame contents of FIGS. 40A and 40B. FIGS. 39A to 39D are different fromFIG. 40C in terms of a state that follows finalization of a write-oncetype information storage medium. For example, as shown in FIG. 39C,after information contained in the bordered area BRDA#3 has beenrecorded, in the case where an attempt is made to achieve finalization,a border out area BRDO is formed immediately after the bordered areaBDA#3 as a border closing process. Then, a terminator area TRM is formedafter the border out area DRDO which immediately follows the borderedarea BRDA#3, thereby reducing a time required for finalization. In theembodiment shown in FIGS. 40A to 40D, there is a need for padding aregion that immediately precedes the extended spare area ESPA withborder out area BRDO. There occurs a problem that a large amount of timeis required to form this border out area BRDO, thereby extending thefinalization time.

In contrast, in the embodiment shown in FIG. 39C, a comparatively shortterminator area TRM is set in length; all of the outer areas than theterminator TRM are redefined as a data lead-out area NDTLDO; and anunrecorded portion which is outer than the terminator TRM is set as auser disable area 911. That is, when the data area DTA is finalized, theterminator area TRM is formed at the end of recording data (immediatelyafter the border out area BRDO). All the information on the main datacontained in this area is set to “00h”. Type information on this area isset in an attribute of the data lead-out area NDTLDO, whereby thisterminator area TRM is redefined as a new data lead-out area NDTLDO, asshown in FIG. 39C. Type information on this area is recorded in areatype information 935 contained in data ID, as described later. That is,the area type information 935 contained in the data ID in thisterminator area TRM is set to “10”, as shown in FIGS. 50A to 50D,thereby indicating that data exists in the data lead-out area DTLDO. Thepresent embodiment is featured in that identification information on adata lead-out position is set by the data ID internal area typeinformation 935.

In an information recording/reproducing apparatus or an informationreproducing apparatus shown in FIG. 11, let us consider a case in whichan information recording/reproducing unit 141 has provided a randomaccess to a specific target position on a write-once type informationstorage medium. Immediately after random access, the informationrecording/reproducing unit 141 must reproduce a data ID and decode adata frame number 922 in order to know where on the write-once typeinformation storage medium has been reached. In the data ID, area typeinformation 935 exists near the data frame number 922. At the same time,it is possible to immediately identify whether or not the informationrecording/recording unit 141 exists in the data lead-out area DTLDOmerely by decoding this area type information 935. Thus, asimplification and high speed access control can be made. As describedabove, identification information on the data lead-out area DTLDO isprovided by data ID internal setting of the terminator area TRM, therebymaking it easy to detect the terminator area TRM.

As a specific example, in the case where the border out area BRDO is setas an attribute of the data lead-out area NDTLDO (that is, in the casewhere the area type information 935 contained in the data ID of a dataframe in the border out BRDO is set to “10b”), the setting of thisterminator area TRM is not provided. Therefore, when the terminator areaTRM is recorded, the area having an attribute of the data lead-out areaNDTLDO, this terminator area TRM is regarded as part of the datalead-out area NDTLDO, thus disabling recording into the data area DTA.As a result, as in FIG. 39C, a user disable area 911 may remain.

In the present embodiment, the size of the terminator area TRM ischanged depending on a location on a write-once type information storagemedium, thereby reducing a finalization time and achieving efficientprocessing. This terminator area TRM indicates an end position ofrecording data. In addition, even in the case where this area is used ina read-only apparatus, which carries out track shift detection inaccordance with a DPD technique, the terminator area, is utilized toprevent overrun due to a track shift. Therefore, a width in a radialdirection on the write-once type information storage medium having thisterminator area TRM (width of a portion padded with the terminator areaTRM) must be a minimum of 0.05 nm or more because of the detectioncharacteristics of the read-only apparatus. A length of one cycle on thewrite-once type information storage medium is different depending on aradial position, and thus, the number of physical segment blocksincluded in one cycle is also different depending on the radialposition. Thus, the size of the terminator area TRM is differentdepending on the physical sector number of a physical sector which ispositioned at the beginning of the terminator area TRM, and the size ofthe terminator area TRM increases as the physical sector go to the outerperiphery side. A minimum value of a physical sector number of anallowable terminator area TRM must be greater than “04FE00h”. Thisderived from a restrictive condition in which the first bordered areaDRDA#1 is composed of 4080 or more physical segment blocks, making itnecessary for the first bordered area BRDA#1 to have a width equal to orgreater than 1.0 mm in a radial direction on the write-once typeinformation storage medium. The terminator area TRM must start from aboundary position of physical segment blocks.

In FIG. 39D, a location in which each item of information is to berecorded is set for each physical segment block size for the reasondescribed previously, and a total of 64 KB user data recorded to bedistributed in 32 physical sectors is recorded in each physical segmentblock. A relative physical segment block number is set with respect to arespective one item of information, as shown in FIG. 39D, and the itemsof information are sequentially recorded in the write-once typeinformation storage medium in ascending order from the lowest relativephysical segment number. In the embodiment shown in FIGS. 39A to 39D,copies CRMD#0 to CRMD#4 of RMD, which are the same contents, areoverwritten five times in a copy information recording zone C_TRZ of thecontents recorded in the recording management zone shown in FIG. 40D.The reliability at the time of reproduction is improved by carrying outsuch overwriting, and, even if dust or scratch adheres onto a write-onceinformation storage medium, the copy information CRMD on the contentsrecorded in the recording management zone can be stably reproduced.Although the border end mark STB shown in FIG. 39D coincides with aborder end mark STB shown in FIG. 40D, the embodiment shown in FIG. 39Ddoes not have the mark NBM indicating a next border, unlike theembodiment shown in FIG. 40D. All the information on the main datacontained in reserved areas 901 and 902 is set to “00h”.

At the beginning of the border-in area BRDI, information which iscompletely identical to updated physical format information U_PFI ismultiply written six times from N+1 to N+6, configuring the updatedphysical format information U_PFI shown in FIG. 40D. The thus updatedphysical format information U_PFI is multiply written, thereby improvingthe reliability of information.

In FIG. 39D, the present embodiment is featured in that the recordingmanagement zone RMZ in the border zone is provided in the border-in areaBRDI. As shown in FIG. 36A, the size of the recording management zoneRMZ contained in the data lead-in area DTLDI is comparatively small. Ifthe setting of a new bordered area BRDA is frequently repeated, therecording management data RMD recorded in the recording management zoneRMZ is saturated, making it impossible to set a new bordered area BRDAmidway. As in the embodiment shown in FIG. 39D, there is attainedadvantageous effect that a recording management zone for recording therecording management data RMD relating to the bordered area BRDA#3 thatfollows is provided in the border-in area DRDI, whereby the setting of anew bordered area BRDA can be provided a number of times and theadditional writing count in the bordered area BRDA can be significantlyincreased. In the case where the bordered area BRDA#3 that follows theborder-in area BRDI including the recording management zone RMZ in thisborder zone is closed or in the case where the data area DTA isfinalized, it is necessary to repeatedly record all the last recordingmanagement data RMD into a spare area 273 (FIG. 38B) established in anunrecorded state in the recording management zone RMZ, and pad all thespare area with the data. In thins manner, the spare area 273 in anunrecorded state can be eliminated, a track shift (due to DPD) at thetime of reproduction in a read-only apparatus can be prevented, and thereproduction reliability of the recording management data RMD can beimproved by multiple recording of the recording management data. All thedata contained in a reserve area 903 are set to “00h”.

Although the border out area BRDO serves to prevent overrun due to atrack shift in the read-only apparatus while the use of DPD is presumed,there is no need for the border-in area BRDI to have a particularlylarge size other than having the updated physical format informationU_PFI and the information contained in recording management zone RMZ inthe border zone. Therefore, an attempt is made to reduce the size to theminimum in order to reduce a time (required for border zone BRDZrecording) at the time of setting a new bordered area BRDA. With respectto FIG. 39A, before forming the border out area BRDO due to borderclosing, there is a high possibility that the user data additionalwriting enable range 205 is sufficiently large, and a large number ofadditional writing is carried out. Thus, it is necessary to largely takea value of “M” shown in FIG. 39D so that recording management data canbe recorded a number of times in the recording management zone RMZ in aborder zone. In contrast, with respect to FIG. 39B, in a state thatprecedes border closing of the bordered area BRDA#2 and that precedesrecording the border out area BRDO, the user data additional writingenable range 205 narrows, and thus, it is considered that not the numberof additional writings of the recording management data to beadditionally written in the recording management zone RMZ in the borderzone does not increase so much. Therefore, the setting size “M” of therecording management zone RMZ in the border-in area BRDI thatimmediately precedes the bordered area BRDA#2 can be taken to berelatively small. That is, as a location in which the border-in areaBRDI is arranged goes to the inner periphery side, the number ofpredicted additional writings of the recording management dataincreases. As the location goes to the outer periphery, the number ofpredicted additional writings of the recording management datadecreases. Thus, the present embodiment is featured in that the size ofthe border-in area BRDI is reduced. As a result, the reduction of a timefor setting a new bordered area BRDA and processing efficiency can beachieved.

A logical recording unit of the information recorded in the borderedarea BRDA shown in FIG. 40C is referred to as an R zone. Therefore, onebordered area BRDA is composed of at least one or more R zones. In acurrent DVD-ROM, as a file system, there are employed a file systemcalled a “UDF bridge” in which both of file management information whichconforms with a UDF (Universal Disc Format) and file managementinformation which conforms with ISO 9660 are recorded in one informationstorage medium at the same time. In a file management method whichconforms with ISO 9660, there is a rule that one file must becontinuously recorded in an information storage medium. That is,information contained in one file is disabled to be divisionallyarranged at a discrete position on an information storage medium.Therefore, for example, in the case where information has been recordedin conformance with the above UDF bridge, all the informationconfiguring one file is continuously recorded. Thus, it is possible toadapt this area in which one file is continuously recorded so as toconfigure one R zone.

FIGS. 41A to 41D show a data structure in the control data zone CDZ andthe R-physical information zone RIZ. As shown in FIG. 41B, physicalformat information (PFI) and disc manufacturing information (DMI) existin the control data zone CDZ, and similarly, an DMI (Disc ManufacturingInformation) and R_PFI (R-Physical Format Information) are contained inan R-physical information zone RIZ.

Information 251 relating to a medium manufacture country and mediummanufacturer's nationality information 252 are recorded in mediummanufacture related information DMI. When a commercially availableinformation storage medium infringes a patent, there is a case in whichan infringement warning is supplied to such a country in which amanufacturing location exists or an information storage medium isconsumed (or used). A manufacturing location (country name) isidentified by being obliged to record the information contained in aninformation storage medium, and a patent infringement warning is easilysupplied, whereby an intellectual property is guaranteed, and technicaladvancement is accelerated. Further, other medium manufacture relatedinformation 253 is also recorded in the medium manufacture relatedinformation DMI.

The present embodiment is featured in that type of information to berecorded is specified depending on a recording location (relative byteposition from the beginning) in physical format information PFI orR-physical format information R_PFI. That is, as a recording location inthe physical format information PFI or R-physical format informationR_PFI, common information 261 in a DVD family is recorded in an 32-bytearea from byte 0 to byte 31; common information 262 in an HD DVD familywhich is the subject of the present embodiment is recorded in 96 bytesfrom byte 32 to byte 127; unique information (specific information) 263relating to various specification types or part versions are recordingin 384 bytes from byte 128 to byte 511; and information corresponding toeach revision is recorded in 1536 bytes from byte 512 to byte 2047. Inthis way, the information allocation positions in the physical formatinformation are used in common depending on the contents of information,whereby the locations of the recorded information are used in commondepending on medium type, thus making it possible to carry out in commonand simplify a reproducing process of an information reproducingapparatus or an information recording/reproducing apparatus. The commoninformation 261 in a DVD family recorded in byte 0 to byte 31, as shownin FIG. 41D, is divided into: information 267 recorded in common in allof a read-only type information storage medium and a rewritable-typeinformation storage medium, and a write-once type information storagemedium recorded from byte 0 to byte 16; and information 268 which isrecorded in common in the rewritable-type information storage medium andthe write-once type information storage medium from byte 17 to byte 31and which is not recorded in the read-only type medium.

FIGS. 55A to 55C show another embodiment relating to a data structure inthe control data zone shown in FIGS. 41A to 41D. As shown in FIG. 35C,the control data zone CDZ is configured as part of an emboss bit area211. This control data zone CDZ is composed of 192 data segments startfrom physical sector number 151296 (024F00h). In the embodiment shown inFIGS. 55A to 55C, a control data section CTDS composed of 16 datasegments and a copyright data section CPDS composed of 16 data segmentsare arranged on two by two basis in the control data zone CDZ, and areserve area RSV is set between these two sections. By allocating thesesections on a two by two basis, a physical distance between the twosections is widened, and an effect relevant to a burst error whichoccurs due to a scratch of an information storage medium surface or thelike is reduced.

In one control data section CTDS, as shown in FIG. 55C, physical sectorinformation on first three relative sector numbers “0” to “2” isrecorded to be repeated 16 times. Multiple writing is carried out 16times, thereby improving the reliability of recording information.Physical format information PFI described in FIG. 42 or 54 is recordedin a first physical sector in a data segment whose relative physicalsector number is “0”. Disc manufacture related information DMI isrecorded in a second physical sector in a data segment whose relativephysical sector number is “1”. Furthermore, copyright protectioninformation CPI is recorded in the third physical sector in the datasegment in which relative number of the physical sector is “2”. Areserved area RSV whose relative physical sector number is “3” to “31”is reserved so as to be available in a system.

As the contents of the above described disc manufacture relatedinformation DMI, a disc manufacturer's name (Disc Manufacturer's name)is recorded in 128 bytes from byte 0 to byte 127; and information on alocation in which a manufacturer exists (information indicating wherethis disc has been manufactured” is recorded in 128 bytes from byte 128to byte 255.

The above disc manufacturer's name is described in ASCII codes. However,the ASCII codes available in use as a disc manufacturer's name arelimited to a starting byte to “0Dh” and “20h” to “7Eh”. A discmanufacture's name is described from the first byte 1 in this area, andthe remaining portions in this area are padded (terminated) with data“0Dh”.

With respect to information on a location in which the above discmanufacturer exists, the information indicating where this disc has beenmanufactured, a country or a region is described in the ASCII codes.This area is limited to a starting byte to “0Dh” and “20h” to “7Eh”which are available ASCII codes as in the disc manufacturer's name. Theinformation on a location in which a disc manufacturer exists isdescribed from the first byte 1 in this area, and the remaining portionsin this area are padded (terminated) with data “0Dh”. Alternatively,another describing method includes setting an allowable size in therange of the first byte to “0Dh” as the information on a location inwhich a disc manufacturer exists. In the case where the information on alocation in which a disc manufacturer exists is long, the information isterminated at “0Dh”, and a region subsequent to “0Dh” may be padded withdata “20h”.

The reserved area RSV shown in FIG. 55C is fully padded with data “00h”.

FIG. 42 shows a comparison depending on a medium type (read-only type,rewritable-type, or write-once type) of information contained in thephysical format information PFI with the contents of specificinformation contained in the physical format information PFI orR-physical format information R_PFI shown in FIGS. 41A to 41D or FIGS.55A to 55C. As information 267 recorded in common to all of theread-only type, rewritable-type, and write-once type medium in thecommon information 261 in the DVD family, there are sequentiallyrecorded from byte positions 0 to 16: specification type (read-only,rewriting, or write-once) information and version number information;medium size (diameter) and maximum allowable data transfer rateinformation; a medium structure (single layer or double layer or whetheror not emboss pit, additional writing area, or rewriting area exists); arecording density (line density and track density) information;allocation location information on data region DTA; and information onwhether or not burst cutting area BCA exists (both of them exist in thepresent embodiment).

As information 268 in common information 261 of a DVD family andrecorded in common to a rewriting type and a write-once type, there arerecorded: revision number information for sequentially defining amaximum recording speed from byte 28 to byte 31; revision numberinformation for defining a maximum recording speed; a revision numbertable (application revision number); class state information andextended (part) version information. The embodiment is featured in thatthe information contained from byte 28 to byte 31 include revisioninformation according to a recording speed in a recording area ofphysical format information PFI or R-physical format information R_PFI.

Conventionally, upon development of a medium featured in that a mediumrecording speed such as ×2 or ×4 increases, there has been a verycomplicated inconvenience that a specification is newly draftedconcurrently. In contrast, according to the present embodiment, thereare divisionally provided: a specification (version book) in which aversion is changed when the contents have been significantly changed;and a revision book in which the corresponding revision is changed andissued, and only a revision book is issued, the book having updated onlyrevision every time a recording speed is improved. In this manner, anextending function for a medium which supports high speed recording anda specification can be handled by a simple method called revisionchange. Thus, in the case where a high speed recording compatible mediumhas been newly developed, there is attained advantageous effect thathigh speed recording can be carried out.

In particular, the present embodiment is featured in that revisionnumbers can be separately set by a maximum value and a minimum value byseparately providing a field of revision number information defining amaximum recording speed of byte 17 and a field of revision numberinformation defining a minimum recording speed of byte 18. For example,in the case where a recording film capable of carrying out recording ata very high speed has been developed, that recording film is often veryexpensive. In contrast, as in the present embodiment, revision numbersare separately set depending on a maximum value and a minimum value of arecording speed, thereby increasing options of recording mediums whichcan be developed. As a result, there is attained advantageous effectthat a medium capable of carrying out high speed recording or a moreinexpensive medium can be supplied.

An information recording/reproducing apparatus according to the presentembodiment has in advance information on an allowable maximum recordingspeed and an allowable minimum recording speed for each revision. Whenan information storage medium is mounted on this informationrecording/reproducing apparatus, first, the informationrecording/reproducing unit 141 shown in FIG. 11 reads the informationcontained in this physical format information PFI and R-physical formatinformation R_PFI. Based on the obtained revision number information,there are detected by the control unit 143: an allowable maximum speedand an allowable minimum recording speed of an information storagemedium mounted with reference to information on an allowable maximumrecording speed and an allowable minimum recording speed for eachrevision recorded in advance in the memory unit 175; and recording iscarried out at an optimal recording speed based on the result of theidentification.

Though byte positions 197-511 of FIG. 42 are reserved in the physicalformat information PFI, a part (byte positions 256-263) of the reservedarea (byte positions 197-511) in the physical format information of HDDVD-R (corresponding to R-physical format information* of FIG. 42)describes a start physical segment number PSN* of the current border-outand the next border-out. More specifically, byte positions 256-259describe a start physical segment number PSN of the border-out in thecurrent user data zone and byte positions 260-263 describe a startphysical segment number PSN of the border-out in next user data zone.Data “00h” is set in the byte positions 260-263 if the next user datazone is not recorded.

Data format of the start physical segment number PSN of the border-outin the current user data zone described in the byte positions 256-259and that of the start physical segment number PSN of the border-out innext user data zone described in the byte positions 260-263 do notchange even after the data contents are changed. The specific values ofdata described in the start physical segment number PSN of theborder-out in the current user data zone and the start physical segmentnumber PSN of the border-out in next user data zone are only changed.

Now, a description will be given with respect to the significance ofspecific information 263 of the type and version of each of thespecifications from byte 128 to byte 511 shown in FIG. 41C and thesignificance of information content 264 which can be set specific toeach of the revisions from byte 512 to byte 2047. That is, in thespecific information 263 of type and version of each of thespecifications from byte 128 to byte 511, the significance of thecontents of recording information at each byte position coincides with arewritable-type information storage medium of a different typeregardless of a write-once type information storage medium. Theinformation content 264 which can be set specific to each of therevisions from byte 512 to byte 2047 permits the fact that if a revisionis different from another in the same type of medium as well as adifference between a rewritable-type information storage medium and awrite-once type information storage medium whose types are differentfrom each other, the significances of the contents of recordinginformation at byte positions are different from each other.

As shown in FIG. 42, as information contents in the specific information263 on the type and version of each of the specifications which coincidewith each other in significance of the contents of recording informationat byte positions between the rewritable-type information storage mediumand the write-once type information storage medium whose types aredifferent from each other, there are sequentially recorded: discmanufacturer's name information; additional information from the discmanufacturer; recording mark polarity information (identification of“H-L” or “L-H”); line speed information at the time of recording orreproduction; a rim intensity value of an optical system along a radialdirection; and recommended laser power at the time of reproduction(light amount value on recording surface).

In particular, the present embodiment is featured in that recording markpolarity information (Mark Polarity Descriptor (identification of “H-L”or “L-H”) is provided in byte 192. In the conventional rewritable-typeor write-once DVD disc, only a “H-L” (High to Low) recording film whoselight reflection amount in a recording mark is low with respect to anunrecorded state (a state in which reflection level is relatively high:High) has been accepted. In contrast, if a medium requires “high speedrecording compatibility”, “price reduction” or “decrease in cross-erase”and “increase in upper limit value of rewriting count” which arephysical properties, there is a problem that the conventional “H-L”recording film is insufficient. In contrast, the present embodimentallows use of an “L-H” recording film whose light reflection amountincreases in a recording mark as well as only an “H-L” recording film.Thus, there is attained advantageous effect that the “L-H” recordingfilm as well as the conventional “H-L” film is incorporated in thespecification, and selecting options of the recording films areincreased, thereby making it possible to achieve high speed recording orto supply an inexpensive medium.

A specific method for mounting an information recording/reproducingapparatus will be described below. The specification (version book) orrevision book describe both of the reproduction signal characteristicsderived from the “H-L” recording film and the reproduction signalcharacteristics derived from the “L-H” recording film. Concurrently, thecorresponding circuits are provided on a two by two basis in the PRequalizing circuit 130 and Viterbi decoder 156 shown in FIG. 11. When aninformation storage medium is mounted in the information reproductionunit 141, first, the slice level detector circuit 132 for reading theinformation contained in the system lea-in area SYLDI is started up.This slice level detector circuit 132 reads information on polarity of arecording mark recorded in this 192 byte (identification of “H-L” or“L-H”); and then make judgment of “H-L” or “L-H”. In response to thejudgment, after the PR equalizing circuit 130 and a circuitry containedin the Viterbi decoder 156 has been switched, the information recordedin the data lead-in area DTLDI or data area DTA is reproduced. The abovedescribed method can read the information contained in the data lead-inarea DTLDI or data area DTA comparatively quickly, and moreover,precisely. Although revision number information defining a maximumrecording speed is described in byte 17 and revision number informationdefining a minimum recording speed is described in byte 18, these itemsof information are merely provided as range information defining amaximum and a minimum. In the case where the most stable recording iscarried out, there is a need for optimal line speed information at thetime of recording, and thus, the associated information is recorded inbyte 193.

The present embodiment is featured in that information on a rimintensity value of an optical system along a circumferential directionof byte 194 and information on a rim intensity value of an opticalsystem along in a radial direction of byte 195 is recorded as opticalsystem condition information at a position which precedes information ona variety of recording conditions (write strategies) included in theinformation content 264 set specific to each revision. These items ofinformation denote conditional information on an optical system of anoptical head used when identifying a recording condition arranged at theback side. The rim intensity used here denotes a distribution state ofincident light incident to an objective lens before focusing on arecording surface of an information storage medium. This intensity isdefined by a strength value at a peripheral position of an objectivelens (iris face outer periphery position) when a center intensity of anincident light intensity distribution is defined as “1”. The incidentlight intensity distribution relevant to an objective lens is notsymmetrical on a point to point basis; an elliptical distribution isformed; and the rim intensity values are different from each otherdepending on the radial direction and the circumferential direction ofthe information storage medium. Thus, two values are recorded. As therim intensity value increases, a focal spot size on a recording surfaceof the information storage medium is reduced, and thus, an optimalrecording power condition changes depending on this rim intensity value.The information recording/reproducing apparatus recognizes in advancethe rim intensity value information contained in its own optical head.Thus, this apparatus reads the rim intensity values of the opticalsystem along the circumferential direction and the radial direction, thevalue being recorded in the information storage medium, and comparesvalues of its own optical head. If there is no large difference as aresult of the comparison, a recording condition recorded at the backside can be applied. If there is a large difference, there is a need forignoring the recording condition recorded at the back side and startingidentifying an optimal recording condition while therecording/reproducing apparatus carries out test writing by utilizingthe drive test zone DRTZ shown in FIGS. 35B, 35C, 37A to 37F.

Therefore, there is a need for quickly making a decision as to whetherto utilize the recording condition recorded at the back side or whetherto start identifying the optimal recording condition while ignoring theinformation and carrying out test writing by oneself. As shown in FIG.42, there is attained advantageous effect that the rim intensityinformation can be read, and then judgment can be made at a high speedas to whether or not the recoding condition arranged later is met byarranging conditional information on an optical system identified at apreceding position with respect to a position at which the recommendedrecording condition has been recorded.

As described above, according to the present embodiment, there aredivisionally provided: a specification (version book) in which a versionis changed when the contents have been significantly changed; and arevision book in which the corresponding revision is changed and issued,and only a revision book is issued, the book having updated onlyrevision every time a recording speed is improved. Therefore, if arevision number is different from another, a recording condition in arevision book changes. Thus, information relating to a recordingcondition (write strategy) is mainly recorded in the information content264 which can be set specific to each of the revisions from byte 512 tobyte 2047. As is evident from FIG. 42, the information content 264 whichcan be set specific to each of the revisions from byte 512 to byte 2047permits the fact that if a revision is different from another in thesame type of medium as well as a difference between a rewritable-typeinformation storage medium and a write-once type information storagemedium whose types are different from each other, the significances ofthe contents of recording information at byte positions are differentfrom each other.

Definitions of peak power, bias power 1, bias power 2, and bias power 3shown in FIG. 42 coincide with power values defined in FIG. 18. An endtime of a first pulse shown in FIG. 42 denotes T_(EFP) defined in FIG.18; a multi-pulse interval denotes T_(MP) defined in FIG. 18; a starttime of a last pulse denotes T_(SLP) defined in FIG. 18, and a period ofbias power 2 of 2T mark denotes T_(LC) defined in FIG. 18.

FIG. 54 shows another embodiment relating to a data structure in each ofphysical format information and R-physical format information. Further,FIG. 54 comparatively describes “updated physical format information”.In FIG. 54, byte 0 to byte 31 are utilized as a recording area of commoninformation 269 contained in a DVD family, and byte 32 and subsequentare set for each specification.

As is the case with byte positions 197 to 511 shown in FIG. 42, withrespect to HD DVD-R physical format information (R physical formatinformation shown in FIG. 54), some of the byte positions (BP) 256 to263 shown in FIG. 54 can be configured so as to describe PSN of a startposition of a border zone (corresponding to a start physical segmentnumber of a current border-out) and PSN of an updated start position(corresponding to a start physical segment number of a next border-out).

In addition, although not shown, the number of actual maximum readingspeeds guaranteed in the disc is described in the byte position (BP) 32shown in FIG. 54. In BP32, for example, 0001010b corresponds to 1 x, anda channel bit rate of 64.8 Mbps is indicated by this 1 x. The actualmaximum reading speed is calculated by Value×(1/10).

In addition, although not shown, in the byte position (BP) 33 shown inFIG. 54, a “layer format table” can be described with respect to aphysical format of HD DVD-R (a double-layered disc having Layer 0 andLayer 1). This table can be composed of 8 bits. Among them, 3 bitsindicate a format of Layer 0 (for example, if these 3 bits are 000b, itindicates an HD DVD-R format), and other 3 bits indicate a format ofLayer 1 (for example, if these 3 bits are 000b, it indicates an HD DVD-Rformat). In a single-side, single-layered R-disc, a layer format tableof BP33 is ignored.

Further, although not shown, the following information can be describedin the byte positions (BP) 133 to 151 shown in FIG. 54. That is, anactual value of an i-th (i=1, 2, . . . 16) recording speed is describedin each of BP133 to 148. The “i-th” used here indicates an i-th minimumspeed from among the speeds applicable in the disc. Therefore, in BP133in which i=1 is set, the lowest recording speed is described. In BP133to BP148, although there are the first to 16th areas of “i”, there is noneed to describe all of these areas. For example, when 00000000b isdescribed (when an i-th recording speed does not exist), it denotes thata byte of the (i-th) area is reserved. Here, the i-th recording speed iscalculated by Value×(1/10).

In BP149, reflectivity of data area is described. When 00101000b isdescribed in BP149, for example, it denotes that the reflectivity is20%. Actual reflectivity is calculated by Value×(1/2) (%).

In BP150, push-pull signal information including a track shape bit isdescribed. When 0b is described in the track shape bit, it denotes thatthe corresponding track is on the groove and 1b is described in thetrack shape bit, it denotes that the corresponding track is on the land.When 0101000b is described in the push-pull signal information, thevalue of the push-pull signal information is, for example, 0.40. Actualamplitude value of the push-pull signal information((I1−I2)pp/(I1+I2)DC), described later) is calculated by Value×(1/100).

In BP151, an amplitude of an on-track signal is described. When01000110b is described in the BP151, it denotes that the amplitude ofthe on-track signal is, for example, 0.70. Actual amplitude value of theon-track signal is calculated by Value×(1/100).

In a write-once type information storage medium, as shown in FIG. 35C,with respect to R-physical format information recorded in an R-physicalinformation zone RIZ contained in the data lead-in area DTLDI, borderzone start position information (first border outermost peripheryaddress) is added to the physical format information PFI (copy of HD DVDfamily common information), and the added information is described. Inthe updated physical format information U_PFI, updated in the border-inarea BRDI shown in FIGS. 40A to 40D or FIGS. 39A to 39D, start positioninformation (self-border outermost periphery address) is added to thephysical format information (copy of HD DVD family common information),and the added information is recorded. In FIG. 42, this border zonestart position information is recorded from byte 197 to byte 204. Incontrast, the embodiment shown in FIG. 54 is featured in thatinformation is recorded at byte 133 to byte 140 which are positionspreceding information relating to a recording condition such as peakpower or bias power 1 (information content 264 which can be set specificto each revision), the position following the common information 269contained in the DVD family. The updated start position information isalso arranged in byte 133 to byte 140 which are positions precedinginformation relating to a recording condition such as peak power or biaspower 1 (information content 264 which can be set specific to eachrevision), the position following the common information 269 containedin the DVD family.

If revision number is upgraded and a recording condition for highprecision is required, there is a possibility that the recordingcondition information contained in the rewritable-type informationstorage medium uses byte 197 to byte 207. In this case, as in theembodiment shown in FIG. 42, if the border zone start positioninformation for R-physical format information recorded in the write-oncetype information storage medium is arranged in byte 197 to byte 204,there is a danger that a correlation (compatibility) between therewritable-type information storage medium and the write-once typeinformation storage medium relating to the arranged position of therecording condition is distorted. As shown in FIG. 54, there is attainedadvantageous effect that the border zone start position information andthe updated start position information are arranged in byte 133 to byte140, thereby making it possible to record a correlation (compatibility)in recording position of a variety of information between therewritable-type information storage medium and the write-once typeinformation storage medium even if an amount of information relating toa recording condition will be increased in the future. With respect tothe specific contents of information relating to the borer zone startposition information, the start position information on the border outarea BRDO situated at the outside of the (current) bordered area BRDAcurrently used in byte 133 to byte 136 is described in PSN (PhysicalSector Number); and border-in area BRDI start position informationrelating to the bordered area BRDA to be used next is described in thephysical sector number (PSN) in byte 137 to byte 140.

The specific contents of information relating to the updated startposition information indicate the latest border zone positioninformation in the case where a bordered area BRDA has been newly set.The start position information on the border out area BRDO situated atthe outside of the (current) bordered area BRDA currently used in byte133 to byte 136 is described in PSN (Physical Sector Number); and thestart position information on the border-in area BRDI relating to thebordered area BRDA to be used next is described in the sector number(PSN) in byte 137 to byte 140. In the case where recording cannot becarried out in the next bordered area BRDA, this area (ranging from byte137 to byte 140) is padded with all “100h”.

As compared with the embodiment shown in FIG. 42, in the embodimentshown in FIG. 54, “medium manufacturer's name information” and“additional information from medium manufacturer” are erased, andrecording mark polarity information (identification of “H-L” or “L-H”)is arranged in 128 byte and subsequent.

FIG. 43 shows a comparison of the contents of detailed informationrecorded in the allocation location information on the data area DTArecorded in byte 4 to byte 15 shown in FIG. 42 or 54. The start positioninformation on the data area DTA is recorded in common regardless ofidentification of medium type, physical format information PFI, andR-physical format information R_PFI. As information indicating an endposition, end position information on the data area DTA is recorded in aread-only type information storage medium.

End position information on an additional writing enable range of theuser data is recorded in the physical format information PFI containedin the write-once type storage medium. This positional informationdenotes a position that immediately precedes point δ in an example shownin FIG. 37E, for example.

In contrast, the R-physical format information R_PFI contained in thewrite-once type information storage medium records the end positioninformation on the recorded data contained in the corresponding borderedarea BRDA.

Further, the read-only type information storage medium records the endaddress information contained in “Layer 0” which is a front layer whenseen from the reproduction optical system; and the rewritable-typeinformation storage medium records information on a differential valueof each item of start position information between a land area and agroove area.

As shown in FIG. 35C, a recording management zone RMZ exists in the datalead-in area DTLDI. In addition, as shown in FIG. 40D, the associatedcopy information exists in the border-out zone BRDO as copy informationC_RMZ indicating the contents recorded in the recording management zone.This recording management zone RMZ records RMD (Recording ManagementData) having the same data size as one physical segment block size, asshown in FIG. 36B, so that new recording management data RMD updatedevery time the contents of the recording management data RMD is updatedcan be sequentially added backwardly. A detailed data structure in suchone item of recording management data RMD is shown in each of FIGS. 44,45, 46, 47, 48 and 49. The recording management data RMD is furtherdivided into fine RMD field information RMDF of 2048 byte size. Thefirst 2048 bytes in the recording management data are provided as areserved area.

The next RMD field 0 of 2048 byte size sequentially allocates: formatcode information of recording management data RMD; medium stateinformation indicating a state of the target medium, i.e., (1) in anunrecorded state, (2) on the way of recording before finalizing, or (3)after finalizing; unique disc ID (disc identification information);allocation position information on the data region DTA; allocationposition information on the latest (updated) data area DTA; andallocation position information on recording management data RMD. Theallocation position information on the data area records informationindicating a user data additional writing enable range 204 (FIG. 37D),i.e., start position information on the data area DTA and the endposition information on the user data recording enable range 204 at thetime of an initial state. In the embodiment shown in FIG. 37D, thisinformation indicates a position that immediately precedes point β.

FIG. 114 shows a still another embodiment of another embodiment relatingto the physical format information and R format information described inFIG. 54. As compared with the embodiment shown in FIG. 54, theembodiment shown in FIG. 114 is featured in that there are recorded:

1) Information relevant to a maximum reproduction speed is recorded in a32nd byte;

2) Information relevant to a first recording speed is recorded in a133rd byte;

3) Information relevant to a second recording speed is recorded in a134th byte

. . .

4) Information relevant to a 16th recording speed is recorded in a 148thbyte;

5) Light reflectivity in a data area DTA is recorded in a 149th byte;

6) A track shape and a push-pull signal amplitude are recorded in a150th byte;

7) On-track signal information (in the case of a write-once typeinformation storage medium) or on-track signal information on a landtrack (in the case of a rewritable type information storage medium) isrecorded in a 151st byte;

8) On-track signal information on a groove track in a rewritable typeinformation storage medium is recorded in a 152nd byte; and

9) A physical sector number or a physical segment number (PSN)indicating a start position of a border zone in R physical formatinformation is recorded in 256th to 263rd bytes and an updated physicalsector number or physical segment number (PSN) indicating a startposition of a border zone is recorded in updated physical formatinformation.

A detailed description will be given below with respect to “informationrelevant to the maximum reproduction speed” recorded in the 32nd byte ofFIG. 114. The “information relevant to the maximum reproduction speed”field records information by a value of x/10 relevant to a case in whichinformation on 1 x representing the standard reproduction speed isdefined as 1. For example, in the case where the maximum reproductionspeed is standard x1, 1=10/10 is obtained. Therefore, a value of “10” isentered in the field of this information (information relevant to themaximum reproduction speed). In addition, for example, in the case wherethe maximum reproduction speed is twice the standard speed (x2), 20/10of the standard speed is obtained. Thus, a value of “20” is recordedinstead of “2” in the field “information relevant to what degree ofspeed is produced as the maximum reproduction speed”.

In the same manner as that described above, the information relevant toan n-th recording speed recorded in the 133rd to 148th bytes is alsorecorded by a value of “x/10 relevant to the standard speed”. Forexample, in the case where the first recording speed is equal to thestandard speed, i.e., x1, 10/10 of the standard speed is obtained. Thus,a value of “10” is recorded as information relevant to the 1st recordingspeed. Data is actually recorded in binary notation, and thus, the valueof “10” is recorded as “0000 1010b”. In addition, in the case whereinformation relevant to the second recording speed recorded in the 134thbyte is obtained to be twice the standard speed, the standardspeed×20/10 is obtained. Thus, binary data “0001 0100b” indicating adecimal value of “20” is recorded in this field. In the case where therecording speed of the target write-once type information storage mediumis defined as only “the standard speed (x1)”, all the fields“information relevant to the second or more recording speeds” describedin the 134th to 148th bytes are handled as reserved areas, and a valueof “0000 0000b” is recorded.

The light reflectivity in the data area DTA recorded in the 149th byteshown in FIG. 114 is recorded by a value obtained by multiplying 1/2with respect to the value obtained by representing an actual value bypercent. For example, in the case where the reflectivity in the dataarea DTA is 20%, 20=40/2 is obtained. Thus, binary data “0010 1000b”indicating a decimal value of 40 is recorded as the data.

The track shape and push-pull signal amplitude that exist in the 150thbyte shown in FIG. 114 are recorded as total 1-byte information. Trackshape information is recorded in the first significant 1 bit, andinformation on the push-pull signal amplitude is recorded in the leastsignificant 7 bits. In the track shape of the significant 1 bit, in thecase where a track exists on a groove area, i.e., in the case where arecording mark is formed on the groove area, “0b” is set as a value ofthis track shape. In the case where a track exists on a land (in thecase where a recording mark is formed on a land area), a value of “1b”is set as the track shape. With respect to an amplitude value of thepush-pull signal recorded in the least significant 7 bits, a push-pullsignal is defined as ((I1−I2)_(pp)/(I1+I2)_(DC)) by a value indicating afraction calculation result whose denominator is a component of output((I1+I2)_(DC)) of an adder 26 shown in FIG. 90A in a state in which arecording mark is not recorded (unrecorded) and whose numerator is anamplitude (I1−I2)_(pp) of a (I1−I2) signal shown in FIGS. 82A and 82B.

In the information reproducing apparatus or informationrecording/reproducing apparatus shown in FIG. 13, a wobble signaldetecting section 135 is used for track shift detection using apush-pull signal. In the track shift detecting circuit (wobble signaldetecting section 135), as a value of the above push-pull signal(I1−I2)_(pp)/(I1+I2)_(DC), track shift detection can be stably carriedout in the range of 0.1≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.8. In particular,with respect to an “H-L” recording film, track shift detection can becarried out more stably in the range of0.26≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.52; and with respect to a “L-H”recording film, track shift detection can be carried out more stably inthe range of 0.30≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.60.

Therefore, in the present embodiment, information storage mediumcharacteristics are defined so that a push-pull signal is included inthe range of 0.1≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.8 (preferably, in the rangeof 0.26≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.52 with respect to the “H-L”recording film and in the range of 0.30≦(I1−I2)_(pp)/(I1+I2)_(DC)≦0.60with respect to the “L-H” recording film. The above range is defined soas to be established in both of a recorded location in data lead-in areaDTLDI or data area DTA and data lead-out area DTLDO (location in which arecording mark exists) and an unrecorded location (location in which norecording mark exists). However, in the present embodiment, withoutbeing limited thereto, this range can be defined so as to be establishedin only the recorded location (location in which a recording markexists) or in only the unrecorded location (location in which norecording mark exists). Further, in the present embodiment, as a ratioof amplitudes (I1−I2)_(pp after) and (I1−I2)_(pp before) of an (I1−I2)signal shown in FIGS. 82A and 82B in the recorded location and in theunrecorded location, the information storage medium characteristics aredefined so as to meet 0.7≦(I1−I2)_(pp after)/(I1−I2)_(pp before)≦1.50regardless of the “H-L” recording film or the “L-H” recording film,whichever may be used. The values of the track shape and the push-pullsignal amplitude described in the least significant 7 bits within thepush-pull signal amplitude are displayed by percentage relevant to anactual push-pull signal amplitude value. For example, in the case wherethe amplitude of the push-pull signal is 0.70 (70%), 0.7=70/100 isobtained. Thus, as the data described in this field, information “01000110b” is described, the information expressing a decimal value of “70”in binary notation.

In the case of a write-once type information recording medium, “on-tracksignal information” is recorded in the 151st bit shown in FIG. 114. Inthe present embodiment, in the write-once type information storagemedium, tracking is carried out on a pre-groove area (a recording markis formed on the pre-groove area). Thus, this on-track signal denotes adetection signal level when tracking is carried out on the pre-groovearea. That is, the above-described on-track information denotes a signallevel (Iot)_(groove) of an unrecorded area when a track loop shown inFIG. 90B or FIG. 91B, for example is turned ON. The information actuallyrecorded in this field is displayed by percentage like the push-pullsignal amplitude of the 150th byte. For example, in the case where theon-track signal is 0.70 (70%), 0.70=70/100 is obtained. Thus,information “0100 0110b” is described in the on-track signal area, theinformation expressing a decimal value of “70” in binary notation.

In the 151st byte shown in FIG. 114, on-track signal information on aland track is recorded in the case of a rewritable type informationstorage medium. In addition, in the case of the rewritable typeinformation storage medium, the on-track signal information on a groovetrack is recorded in the 152nd byte shown in FIG. 114. Like the on-tracksignal information described previously, the on-track signal informationon a land track and the on-track signal information on a groove trackare also described by percentage (by x/100). That is, for example, inthe case where the on-track signal on the land track or groove track is0.70, 70/100 is obtained. Thus, information “0100 0110b” is described,the information expressing a decimal value of “70” in binary notation.

R physical format information is recorded in the 256th to 263rd bytesshown in FIG. 114, and information indicating a start position of aborder zone is recorded in updated physical format information. In the Rphysical format information, a physical sector number representing thestart position of current border-out BRDO (refer to FIG. 39C) isrecorded in the 256th to the 259th bytes; and information on thephysical sector number PSN indicating the start position of border-inBRDI that corresponds to a next bordered area is recorded in the 260thto the 263rd bytes. In the updated physical format information, aphysical sector number or a physical segment number (PSN) representing astart position of next border-out BRDO (refer to FIG. 39C) is recordedin the 256th to the 259th bytes, and a physical sector number or aphysical segment number (PSN) representing the start position of nextborder-in BRDI is recorded in the 260th to the 263rd bytes. Here, in thecase where a next bordered area BRDA does not exist, “00h” is recordedas a physical sector number or a physical segment number (PSN)indicating the start position of the next border-in.

FIG. 115 shows detailed information on setting location informationcontained in the data area DTA recorded in the 4th to 15th bytes shownin FIG. 54 or setting location information contained in the data areaDTA allocated in the 4th to 15th bytes shown in FIG. 114. The settinglocation information contained in the data area DTA shown in FIG. 115 isrecorded as slightly different items of information in the physicalformat information PFI, the R physical format information R-PFI, and theupdated physical format information U-PFI. That is, in a reproductiononly type information storage medium, first, the start positioninformation contained in the data area is recorded by a physical sectoror a physical segment number (PSN). Next, the end position informationcontained in the data area is recorded. Lastly, the last addressinformation on Layer 0 (layer L0) is further recorded as a physicalsector or physical segment information, respectively.

In contrast, in a rewritable type information storage medium, the startposition information contained in the data area DTA of the inside of theland area; the end position information contained in the data area DTAinside the land area; and a differential value of items of the startposition information between the land area and the groove area arerecorded by a physical sector number or a physical segment number,respectively.

In a write-once type information storage medium, there are recorded: aphysical sector number or a physical segment number (PSN) representingthe start position information contained in a data area; and a physicalsector number or a physical segment number (PSN) representing the lastposition information in the range such that user data can be writtenonce. In the present embodiment, the start position informationcontained in the data area of the write-once type information storagemedium, as shown in FIG. 37D, is recorded by a physical sector number ora physical segment number (PSN) representing a first position of thedata area DTA, and a value of “030000h” is substantially recorded. Inaddition, as the last position information in the range such that theuser data can be written once, information immediately preceding aposition of β that is the last position of the data area DTA is recordedas shown in FIG. 37D, and a value of “73543Fh” is substantiallyrecorded. However, in the write-once type information storage mediumaccording to the present embodiment, at a first state, as shown in FIG.37F, in the case where an extended substitute area is first set as ESPA,recording can only be carried out while a user data available range 2 islimited to a position immediately preceding a zeta (ζ) point. Thus, aphysical sector number or a physical segment number (PSN) is recorded,the number indicating a position immediately preceding the zeta point.

In R physical format information R_PFI, a physical sector number(030000h) is recorded, the number representing the start positioninformation contained in the data area DTA. In addition, a physicalsector number is recorded, the number indicating a location in whichlast recording has been made in the last R zone included in the borderedarea.

In updated physical format information U_PFI, there are recorded: aphysical sector number (030000h) representing the start positioninformation contained in the data area DTA; and a physical sector numberindicating a location in which last recording has been made in the lastR zone included in the bordered area.

The present embodiment, as shown in FIGS. 37E and 37F, is featured inthat an extended drive test zone EDRTZ and an extended spare area ESPAcan be additionally set in the user data additional writing enable range204. However, such extension narrows a user data additional writingenable range 205. The present embodiment is featured in that associatedinformation is recorded in “allocation position information on thelatest (updated) data area DTA” so as not to additionally write the userdata in these extended areas EDRTZ and ESPA. That is, it is possible toidentify whether or not the extended drive test zone EDRTZ has beenextended based on the identification information on the presence orabsence of the extended drive test zone EDRTZ, and it is possible toidentify whether or not the extended spare area ESPA has been extendedbased on identification information on the presence or absence of theextended spare area ESPA. Further, the recording enable rangeinformation relating to the user data additional writing enable range205 managed in the recording management data RMD includes the endposition of the latest user data recording enable range 205 recorded inthe allocation position information on the data area DTA in the RMDfield 0 as shown in FIG. 44. Therefore, the user data recording enablerange 205 shown in FIG. 37F can be identified immediately, enabling highspeed detection of a size of an unrecorded area in which recording canbe carried out in the future (the residual amount of unrecorded area).In this manner, for example, there is attained advantageous effect thata transfer rate at the time of optimal recording is set in conformancewith the user specified image recording reserved time, thereby making itpossible to fully record an image in a medium during the user specifiedimage recording reserved time. By way of example of the embodiment shownin FIG. 37D, “the end position of the latest user data recording enablerange 205” denotes a position that precedes point ζ.

These items of positional information can be described in ECC blockaddress numbers according to another embodiment instead of beingdescribed in physical sector numbers. As described later, in the presentembodiment, one ECC block is composed of 32 sectors. Therefore, theleast significant five bits of the physical sector number of a sectorarranged at the beginning in a specific ECC block coincides with that ofa sector arranged at the start position in the adjacent ECC block. Inthe case where a physical sector number has been assigned so that theleast significant five bits of the physical sector of the sectorarranged at the beginning in the ECC block is “00000”, the values of theleast significant six bits or more of the physical sector numbers of allthe sectors existing in the same ECC block coincide with each other.Therefore, address information obtained by eliminating the leastsignificant five bit data of the physical sector numbers of the sectorsexisting in the same ECC block as above and sampling only data of theleast significant six bit and subsequent is defined as ECC block addressinformation (or ECC block address number). As described later, the datasegment address information (or physical segment block numberinformation) recorded in advance by wobble modulation coincides with theabove ECC block address. Thus, when the positional information containedin the recording management data RMD is described in the ECC blockaddress numbers, there is attained advantageous effects described below:

1) An access to an unrecorded area is accelerated in particular:

A differential calculation process is facilitated because a positionalinformation unit of the recording management data RMD coincides with aninformation unit of data segment addresses recorded in advance by wobblemodulation; and

2) A management data size in the recording management data RMD can bereduced:

The number of bits required for describing address information can bereduced by 5 bits per address.

As described later, a single physical segment block length coincideswith a one data segment length, and the user data for one ECC block isrecorded in one data segment. Therefore, an address is expressed as an“ECC block address number”; an “ECC block address”; a “data segmentaddress”, a “data segment number”, or a “physical segment block number”and the like. These expressions have the same meaning.

As shown in FIG. 44, in the allocation position information on therecording management data RMD existing in RMD field 0, size informationin that the recording management zone RMZ capable of sequentiallyadditionally writing the recording management data RMD is recorded inECC block units or in physical segment block units. As shown in FIG.36B, one recording management zone RMD is recorded on one by onephysical segment block basis, and thus, based on this information, it ispossible to identify how many times the updated recording managementdata RMD can be additionally written in the recording management zoneRMZ. Next, a current recording management data number is recorded in therecording management zone RMZ. This denotes number information on therecording management data RMD which has been already recorded in therecoding management zone RMZ. For example, assuming that thisinformation corresponds to the information contained in the recordingmanagement data RMD#2 as an example shown in FIG. 36B, this informationcorresponds to the second recorded recording management data RMD in therecoding management zone RMZ, and thus, a value “2” is recorded in thisfield. Next, the residual amount information contained in the recordingmanagement zone RMZ is recorded. This information denotes information onthe item number of the recording management data RMD which can befurther added in the recording management zone RMZ, and is described inphysical segment block units (=ECC block units=data segment units).Among the above three items of information, the following relationshipis established.

[Size information having set RMZ therein]=[Current recording managementdata number]+[residual amount in RMZ]

The present embodiment is featured in that the use amount or theresidual amount information on the recording management data RMDcontained in the recording management zone RMZ is recorded in arecording area of the recording management data RMD.

For example, in the case where all information is recorded in onewrite-once type information storage medium once, the recordingmanagement data RMD may be recorded only once. However, in the casewhere an attempt is made to repeatedly record additional writing of theuser data (additional writing of the user data in the user dataadditional writing enable range 205 in FIG. 37F) very finely in onewrite-once type information storage medium, it is necessary toadditionally write recording management data RMD updated every timeadditional writing is carried out. In this case, if the recordingmanagement data RMD is frequently additionally written, the reservedarea 273 shown in FIG. 36B is eliminated, and the informationrecording/reproducing apparatus requires countermeasures against thiselimination. Therefore, the use amount or residual amount information onthe recording management data RMD contained in the recording managementzone RMZ is recorded in a recording area of the recording managementdata RMD, thereby making it possible to identify in advance a state inwhich additional writing in the recording management zone RMZ cannot becarried out and to take action by the information recording/reproducingapparatus earlier.

As shown in FIGS. 37E to 37F, the present embodiment is featured in thatthe data lead-out area DTLDO can be set in the form such that theextended drive test zone EDRTZ is included (FIG. 1 (E4)). At this time,the start position of the data lead-out area DTLDO changes from point βto point ε. In order to manage this situation, there is provided a fieldfor recording the start position information on the data lead-out areaDTLDO in the allocation position information of the latest (updated)data area DTA of the RMD field shown in FIGS. 44 to 49. As describedpreviously, a drive test (test writing) is basically recorded in clusterunits which can be extended in data segment (ECC block) units.Therefore, although the start position information on the data lead-outarea DTLDO is described in the ECC block address numbers, thisinformation can be described in the physical sector number or physicalsegment block number, data segment address, or ECC block address of aphysical sector first arranged in this first ECC block according toanother embodiment.

In an RMD field 1, there are recorded: update history information on aninformation recording/reproducing apparatus in which recording of thecorresponding medium has been carried out. This information is describedin accordance with a format of all recording condition informationcontained in information 264 (FIG. 42) in which manufactureridentification information for each information recording/reproducingapparatus; serial numbers and model numbers described in ASCII codes;date and time information when recording power adjustment using a drivetest zone has been made; and recording condition information provided atthe time of additional writing can be set specific to each revision.

An area of “Drive specific data” for recording specific information suchas Write Strategy (refer to FIG. 18) or the like can be provided in #1to #4 of the inside of RMD field 1 shown in FIG. 45. A detaileddescription of RMD field 1 including this “Drive specific data” will begiven with reference to FIG. 113.

An RMD field 2 is a user available area so that a user can recordinformation recorded contents (or contents to be recorded), for example.

The start position information of each border zone BRDZ is recorded inan RMD field 3. That is, as shown in FIG. 45, the start positioninformation from the start to the fiftieth border out areas BTDOs isdescribed in the physical sector numbers.

For example, in the embodiment shown in FIG. 40C, the start position ofthe first border out area BRDO indicates a position of point η, and thestart position of the second BRDO indicates a position of point θ.

The positional information on an extended drive test zone is recorded inan RMD field 4. First, there are recorded: the end position informationon a location which has already been used for test writing in the drivetest zone DRTZ which exists in the data lead-in area DTLDI described inFIG. 36C; and the end position information on a location which hasalready been used for test writing in the drive test zone DRTZ whichexists in the data lead-out area DTLDO described in FIGS. 37D to 37F.

In the drive test zone DRTZ, the above position information issequentially used for test writing from the inner periphery side (fromthe lowest physical sector number) to the outer periphery direction (ina direction in which the physical sector number is higher). Test writingis carried out in cluster units which are units of additional writing,as described later, and thus, ECC block units are used as locationunits. Therefore, in the case where the end position information on thelocation which has been already used for test writing is described inthe ECC address numbers or is described in the physical sector numbers,there are described a physical sector number of a physical sectorarranged at the end of the ECC block which has been used for testwriting. Because a location used for test writing once has already beendescribed, in the case where next test writing is carried out, such testwriting is carried out from a next of the end position which has alreadybeen used for test writing. Therefore, the informationrecording/reproducing apparatus can identify momentarily from where testwriting should be started by using the end position information (=a useamount in the drive test zone DRTZ) on a location which has already beenused in the above drive test zone DRTZ. In addition, based on thatinformation, this apparatus can judge whether or not a free space inwhich next test writing can be carried out exists in the drive test zoneDRTZ.

The drive test zone DRTZ which exists in the data lead-in area DTLDIrecords: flag information indicating whether or not area sizeinformation indicating that additional writing can be carried out; flaginformation indicating that this drive test zone DRTZ has been used upor area size information indicating that additional test writing can befurther carried out in the drive test zone DRTZ which exists in the datalead-out area DLTDI; and area size information indicating thatadditional test writing can further be carried out in the drive testzone DRTZ which exists in the data lead-out area DTLDO or flaginformation indicating whether or not this drive test zone DRTZ has beenused up. The size of the drive test zone DRTZ which exists in the datalead-in area DTLDI and the size of the drive test zone DRTZ which existsin the data lead-out area DTLDO are identified in advance, thus makingit possible to identify the size (residual amount) of an area in whichadditional test writing can be carried out in the drive test zone DRTZonly based on the end position information on a location which hasalready been used for test writing in the drive test zone DRTZ whichexists in the data lead-in area DTLDI or in the drive test zone DRTZwhich exists in the data lead-out area DTLDO. However, this informationis provided in the recording management data RMD, thereby making itpossible to identify the residual amount in the drive test zone DRTZimmediately and to reduce a time required for judging whether or not tonewly set the extended drive test zone EDRTZ. According to anotherembodiment, in this field, it is possible to record: flag informationindicating whether or not this drive test zone DRTZ has been used upinstead of area size (residual amount) information indicating thatadditional writing can further be carried out in the drive test zoneDRTZ. If a flag has already been set to identify momentarily that theabove test zone has already been used up, it is possible to preclude adanger that test writing is carried out in this area.

Additional setting count information on the next extended drive testzone EDRTZ is recorded in the RMD field 4. In the embodiment shown inFIG. 37E, the extended drive test zones EDRTZs are set in two zones,i.e., an extended drive test zone 1 EDRTZ1 and an extended drive testzone 2 EDRTZ2, and thus, “additional setting count of the extended drivetest zone EDRTZ=2” is established. Further, range information for eachextended drive test zone EDRTZ and range information which has alreadybeen used for test writing are recorded in the RMD field 4. In this way,the positional information on the extended drive test zone can bemanaged in the recording management data RMD, thereby enabling extensionsetting of the extended drive test zone EDRTZ a plurality of times. Inaddition, in a write-once type information storage medium, thepositional information on the extended drive test zone EDRTZ which hasbeen sequentially extended can be precisely managed in the form ofupdating and additional writing of the recording management data RMD,and it is possible to preclude a danger that the user data isoverwritten on the extended drive test zone EDRTZ while user dataadditional writing enable range 204 (FIG. 37D) is mistakenly determined.As described above, test writing units are also recorded in clusterunits (ECC block units), and thus, the range of each extended drive testzone EDRTZ is specified in ECC block address units. In the embodimentshown in FIG. 37E, the start position information on the first setextended drive test zone EDRTZ indicates point γ because the extendeddrive test zone 1 EDRTZ1 has been first set; and the end positioninformation on the first set extended drive test zone EDRTZ correspondsto a position that immediately precedes point β. Positional informationunits are described in the address numbers or physical sector numberssimilarly.

While the embodiment of FIGS. 44 and 45 shows the end positioninformation on the extended drive test zone EDRTZ, size information onthe extended drive test zone EDRTZ may be described without beinglimited thereto. In this case, the size of the first set extended drivetest zone 1 EDRTZ1 is set to “β-γ”. The end position information on alocation which has already been used for test writing in the first setextended drive test zone EDRTZ is also described with the ECC blockaddress number or physical sector number. Then, the area sizeinformation (residual amount) in which additional test writing can becarried out in the first set extended drive test zone EDRTZ. The size ofthe extended drive test zone 1 EDRTZ1 and the size of the area, whichhas already been used therein, is already been identified based on theabove described information. Thus, the area size (residual amount) inwhich additional test writing can be carried out is already obtained. Byproviding this field, it is possible to identify immediately whether ornot a current drive test zone will suffice when a new drive test (testwriting) is carried out. In addition, it is possible to reduce ajudgment time required for determining additional setting of a furtherextended drive test zone EDRTZ. In this field, there can be recordedarea size (residual amount) information indicating that additionalwriting can be carried out. According to another embodiment, in thisfield it is possible to set flag information indicating whether or notthis extended drive test zone EDRTZ has been used up. It is possible topreclude a danger that test writing is mistakenly carried out in thisarea, as long as a flag is set to momentarily identify that the testzone has already been used up.

A description will be given with respect to an example of a processingmethod for newly setting an extended drive test zone EDRTZ by theinformation recording/reproducing apparatus shown in FIG. 11 and carriedout test writing in the zone.

1) A write-once type information storage medium is mounted on aninformation recording/reproducing apparatus.

2) Data formed in the burst cutting area BCA is reproduced by theinformation recording/reproducing unit 141; the recorded data issupplied to the control unit 143; and the information is decoded in thecontrol unit 143, and it is determined whether or not processing canproceeds to a next step.

3) Information recorded in the control data zone CDZ in the systemlead-in area SYLDI is reproduced by the informationrecording/reproducing unit 141, and the reproduced information istransferred to the control unit 143.

4) Values of rim intensities (in bytes 194 and 195 shown in FIG. 42)when a recommended recording condition has been identified in thecontrol unit 143 are compared with a value of rim intensity of anoptical head used at the information recording/reproducing unit 141; andan area size required for test writing is identified.

5) The information contained in recording management data is reproducedby the information recording/reproducing unit 141, and the reproducedinformation is transferred to the control unit 143. The control sectiondecodes the information contained in the RMD field 4 and determineswhether or not there is a margin of an area size required for testwriting, the size being identified in step (4). In the case where thejudgment result is affirmative, processing proceeds to step (6).Otherwise, processing proceeds to step (9).

6) A location for starting test writing is identified based on endposition information on a location which has already been used for testwriting in the drive test zone DRTZ or extended drive test zone EDRTZused for test writing from the RMD field 4.

7) Test writing is executed by the size identified in step (4) from thelocation identified in step (6).

8) The number of locations used for test writing has been increased inaccordance with the processing in step (7), and thus, recordingmanagement data RMD obtained by rewriting the end position informationon the locations which has already been used for test writing istemporarily stored in the memory unit 175, and processing proceeds tostep (12).

9) The information recording/reproducing unit 141 reads information on“end position of the latest user data recording enable range 205”recorded in the RMD field 0 or “end position information on the userdata additional writing enable range” recorded in the allocationlocation information on the data area DTA contained in the physicalformed shown in FIG. 43; and the control unit 143 further internallysets the range of a newly set extended drive test zone EDRTZ.

10) Information on “end position of the latest used data recordingenable range 205” recorded in the RMD field 0 based on the resultdescribed in step (9) is updated and additional setting countinformation on the extended drive test zone EDRTZ contained in the RMDfield 4 is incremented by one (that is, the count is added by 1); andfurther, the memory unit 175 temporarily stores the recording managementdata RMD obtained by adding the start/end position information on thenewly set extended drive test zone EDRTZ.

11) Processing moves from step (7) to (12).

12) Required user information additionally written into the user dataadditional writing enable range 205 under an optimal recording conditionobtained as a result of test writing carried out in step (7).

13) The memory unit 175 temporarily stores the recording management dataRMD updated by additionally writing the start/end position information(FIG. 47) contained in an R zone which has been newly generated inresponse to step (12).

14) The control unit 143 controls the information recording/reproducingunit 141 to additionally record the latest recording management data RMDtemporarily stored in the memory unit 175, in the reserved area 273 (forexample, FIG. 36B) contained in the recording management zone RMZ.

As shown in FIG. 47, positional information on the extended spare areaESPA is recorded in an RMD field 5. In the write-once type informationstorage medium, a spare area can be extended, and the positionalinformation on that spare area is managed in the position managementdata RMD. In the embodiment shown in FIG. 37E, the extended spare areaESPA is set in two areas, i.e., an extended spare area 1 ESPAL and anextended spare area 2 ESPA2, and thus, “the number of additionalsettings of the extended space area ESPA” is set to “2”. The startposition information on the first set extended spare area ESPAcorresponds to at a position of point δ; the end position information onthe second set extended spare area ESPA corresponds to at a positionthat precedes point γ; the end position information on the first setextended spare area ESPA corresponds to at a position that precedespoint ξ; and the end position information on the second set extendedspare area ESPA corresponds to at a position of point ε.

The information relating to defect management is recorded in the RMDfield 5 shown in FIG. 47. A first field in the RMD field 5 shown in FIG.47 records ECC block number information or physical segment block numberinformation which has already been used for substitution in the adjacentarea to the data lead-in area DTLDI. In the present embodiment, asubstituting process is carried out in ECC block units with respect to adefect area found in the user data additional writing range 204. Asdescribed later, one data segment configuring one ECC block is recordedin one physical segment block area, and thus, the substitution countwhich has already been done is equal to the number of ECC blocks whichhas already been used (or number of physical segment blocks and numberof data segments). Therefore, the units of information described in thisfield are obtained as ECC block units or physical segment block unitsand data segment units. In the write-once type information storagemedium, in the spare area SPA or extended pare area ESPA, a locationused as a replacing process may be often used sequentially from theinner periphery side having the lowest ECC block address number.Therefore, with respect to the information contained in this field, inanother embodiment, it is possible to describe an ECC block addressnumber as the end position information on a location which has alreadybeen used for substitution. As shown in FIG. 47, with respect to thefirst set extended spare area 1 ESPA1 and the second set extended sparearea 2 ESPA2 as well, there exist fields for recording similarinformation (“ECC block number information or physical segment blocknumber information which have already been used for substitution in thefirst set extended spare area ESPA or end position information (ECCblock address number) on a location which has been used forsubstitution”; and “ECC block number information or physical segmentblock number information which have already been used for substitutionin the second set extended spare area ESPA or end position information(ECC block address number) on a location which has been used forsubstitution”.

Using these items of information, the following advantageous effects areattained:

1) A spare location to be newly set with respect to a defect area foundin the user data additional writing enable range 205 is identifiedimmediately when next substituting process is carried out.

New substitution is carried out immediately after the end position of alocation which has already been used for substitution.

2) The residual amount in the spare area SPA or extended spare area ESPAis obtained by calculation and (in the case where the residual amount isinsufficient), it is possible to identify necessity of setting a newextended spare area ESPA. The size of the spare area SPA adjacent to thedata lead-in area DTLDI is identified in advance, and thus, the residualamount in the spare area SPA can be calculated if there existsinformation relating to the number of ECC blocks which have already beenused in the spare area SPA. However, the residual amount can beidentified immediately by providing a recording frame of the ECC blocknumber information or physical segment block number information in anunused location available for future substitution, which is residualamount information contained in the spare area SPA. Thus, it is possibleto reduce a time required for judgment of the necessity of providingsettings relating to a further extended spare area ESPA. For a similarreason, there is provided a frame capable of recording “residual amountinformation contained in the first set extended spare area ESPA and“residual amount information contained in the second set extended sparearea ESPA. In the present embodiment, a spare area SPA is extensible inthe write-once type information storage medium, and the associatedposition information is managed in the recording management data RMD. Asshown in FIGS. 37A to 37F, it is possible to extensively set an extendedspare area 1 ESPA1 and an extended spare area 2 ESPA2 or the like at anarbitrary start position and at an arbitrary size as required in theuser data additional writing enable range 204. Therefore, the additionalsetting count information on the extended spare area ESPA is recorded inthe RMD field 5, making it possible to set the start positioninformation on the first set extended spare area ESPA or the startposition information on the secondly set extended spare area ESPA. Theseitems of start position information are described in physical sectornumbers or ECC block address numbers (or physical segment block numbersor data segment addresses). In the embodiment shown in FIGS. 44 and 45,“the end position information on the first set extended spare area ESPA”or “the end position information on the second set extended spare areaESPA” are recorded as information for specifying the range of theextended spare area ESPA. However, in another embodiment, in stead ofthese items of end position information, size information on theextended spare area ESPA can be recorded by the ECC block number orphysical segment block number, data segment number, and ECC block numberor physical sector number.

Defect management information is recorded in an RMD field 6. The presentembodiment uses a method for improving reliability of information to berecorded in an information storage medium, the information relating todefect processing, in the following two modes:

1) A conventional “replacing mode” for recording in a spare locationinformation to be recorded in a defect location; and

2) A “multiplying mode” for recording the same contents of informationtwice in a location which is different from another one on aninformation storage medium, thereby improving reliability.

Information as to which mode processing is carried out is recorded in“type information on defect management processing” contained insecondary defect list entry information contained in the recordingmanagement data RMD as shown in FIG. 48. The contents of secondarydefect list entry information are as follows:

1) In the Case of the Conventional Replacing Mode

Type information on defect management processing is set to “01” (in thesame manner as in conventional DVD-RAM);

The “positional information on a replacement source ECC block” used heredenotes positional information on an ECC block found as a defectlocation in the user data additional writing enable range 205, andinformation to be essentially recorded in the range is recorded in aspare area or the like without being recorded in the above range; and

The “positional information on a replacement destination ECC block” usedhere indicates positional information on a location of a replacementsource to be set in the spare area SPA or extended spare area 1 ESPA1,and an extended spare area 2 ESPA2 shown in FIG. 37E, and theinformation to be recorded in a defect location, the information beingfound in the additional writing enable range 205, is recorded in theabove area.

2) In the Case of the Multiplying Mode

Type information on defect management processing is set to “10”;

The “positional information on replacement source ECC block” denotes anon-defect location, and indicates position information in which targetinformation is recorded and the information recorded therein can beprecisely reproduced; and

The “positional information on replacement destination ECC block”indicates positional information on a location in which the completelysame contents as the information recorded in the above described“positional information on replacement source ECC block” are recordedfor the purpose of multiplication set in the spare area SPA or extendedspare area 1 ESPA1 and extended spare area 2 ESPA 2 shown in FIG. 37E.

In the case where recording has been carried out in the above described“(1) conventional replacing mode”, it is confirmed that the informationrecorded in an information storage medium is precisely read out at thestage immediately after recording. However, there is a danger that theabove described information cannot be reproduced due to scratch or dustadhering to an information storage medium, caused by the user's abuse.In contrast, in the case where recording has been carried out in the“(2) multiplying mode”, even if information cannot be partially read inan information storage medium due to a scratch or dust caused by user'sabuse or the like, because the same information is backed up at anotherportion, the reliability of information reproduction is remarkablyimproved. The above backed up information is utilized for theinformation which cannot be read at this time, and the replacing processin “(1) conventional replacing mode” is carried out, thereby furtherimproving reliability. Therefore, there is attained advantageous effectthat high reliability of information reproduction after recorded,considering countermeasures against scratch or dust can be arranged by aprocessing operation in “(1) conventional replacing mode” alone and byusing a combination of the processing operation in “(1) conventionalreplacing mode” and a processing mode in “(2) multiplying mode”. Methodsfor describing the positional information on the above ECC blockinclude: a method for describing a physical sector number of a physicalsector which exists at a start position which configures the above ECCblock and a method for describing an ECC block address, a physicalsegment block address, or a data segment address. As described later, inthe present embodiment, a data area including data of one ECC block sizeis referred to as a data segment. A physical segment block is defined asa physical unit on an information storage medium serving as a locationfor recording data, and one physical segment size coincides with a sizeof an area for recording one data segment.

The present embodiment provides a mechanism capable of recording thedefect position information detected in advance before the replacingprocess. In this manner, the manufacturers of information storagemediums check a defect state in the user data additional writing range204 immediately before shipment. When the detected defect location isrecorded in advance (before the replacing process) or the informationrecording/reproducing apparatus has carried out an initializing processat the user's site, the defect state in the user data additional writingenable range 294 is checked so that the detected defect location can berecorded in advance (before the replacing process). In this way, theinformation indicating a defect position detected in advance before thereplacing process corresponds to “information on the presence or absenceof the process for replacing a defect block with a spare block” (SLR:State of Linear Replacement) contained in the secondary defect listentry information.

When the information SLR on the presence or absence of the process forreplacing a defect block with a spare block is set to “0”:

The replacing process is carried out with respect to a defect ECC blockspecified by “positional information on replacement source ECC block”;and

Information, which can be reproduced, is recorded in a locationspecified by “positional information on replacement destination ECCblock”.

When the information SLR on the presence or absence of the process forreplacing a defect block with a spare block is set to “1”:

A defect ECC block specified by “positional information on replacementsource ECC block” denotes a defect block detected in advance at thestate that precedes the replacing process; and

A field of “positional information on replacement destination ECC block”is blanked (no information is recorded).

When a defect location is thus identified in advance, there is attainedadvantageous effect that an optimal replacing process can be carried outat a high speed (and in a real time) at the stage at which aninformation recording/reproducing apparatus carries out additionalwriting in a write-once type information storage medium. In addition, inthe case where video image information or the like is recorded in theinformation storage medium, it is necessary to guarantee continuity atthe time of recording, and a high speed replacing process based on theabove described information becomes important.

If a defect occurs in the user data additional writing enable range 205,the replacing process is carried out in predetermined location placed inthe spare area SPA or extended spare area ESPA. Every time the replacingprocess is carried out, one item of Secondary Defect List Entryinformation is added; and set information on the positional informationon an ECC block utilized as a substitute of the positional informationon a defect ECC block is recorded in this RMD field 6. When additionalwriting of the user data is newly repeated in the user data additionalwriting enable range 205, if a new defect location is detected, thereplacing process is carried out, and the number of items of thesecondary defect list entry information increases. A managementinformation area (RMD field 6) for defect management can be extended byadditionally writing the recording management data RMD with an increasednumber of items of this Secondary Defect List Entry information into thereserved area 273 contained in the recording management zone RMZ, asshown in FIG. 36B. By using this method, the reliability of defectmanagement information itself can be improved for the reasons describedbelow.

1) The recording management data RMD can be recorded while avoiding adefect location in the recording management zone RMZ.

A defect location may be produced in the recording management zone RMZshown in FIG. 36B. The contents of the recording management data RMDnewly additionally written in the recording management zone RMZ areverified immediately after additional writing, thereby making itpossible to sense a state in which recording cannot be carried out dueto a defect. In that case, the recording management data RMD isrewritten adjacent to the defect location, thereby making it possible torecord the recording management data RMD in the form such that highreliability is guaranteed.

2) Even if the past recording management data RMD cannot be reproduceddue to the scratch adhering to an information storage medium surface, acertain degree of backup can be carried out.

For example, in the case where the example shown in FIG. 36B is taken, astate in which, after recording management data RMD#2 has been recorded,the information storage medium surface is scratched due to the user'smistake or the like, and then, the recording management data RMD#2cannot be reproduced, is presumed as an example. In this case, a certaindegree of the past defect management information (information containedin the RMD field 6) can be recovered by reproducing information on therecording management data RMD#1 instead.

Size information on the RMD field 6 is recorded at the beginning of theRMD field 6, and this field size is made variable, thereby making itpossible to extend the management information area (RMD field 6) fordefect management. Each RMD field is set to 2048 size (for one physicalsector size), as described previously. However, if a plenty of defectsoccur with the information storage medium, and then, the replacingprocess count increases, the size of the Secondary Detect Listinformation increases, and the 2048 byte size (for one physical sectorsize) becomes insufficient. In consideration of this situation, the RMDfield 6 can be set to a plurality of multiples of 2048 size (recordingacross a plurality of sectors can be carried out). Namely, if “the sizeof the RMD field 6” has exceeded 2048 bytes, an area for a plurality ofphysical sectors is arranged to the RMD field 6.

The secondary defect list information SDL records: the secondary defectlist entry information described above; “secondary defect listidentification information” indicating a start position of the secondarydefect list information SDL; and “secondary defect list update counter(update count information)” indicating count information as to how manytimes the secondary defect list information SDL has been rewritten. Thedata size of the whole secondary defect list information SDL can beidentified based on “number information on the secondary defect listentry”.

As described previously, user data recording is locally carried out inunits of R zone in the user data additional writing enable range 205.That is, part of the user data additional writing enable range 205reserved for recoding the user data is referred to as an R zone. This Rzone is divided into two types according to a recording condition. Amongthem, a type of zone in which additional user data can be furtherrecorded is referred to as an Open R Zone, and a type of zone in whichno further user data can be added is referred to as a Complete R Zone.The user data additionally writing enable range 205 cannot have three ormore Open R zones. That is, up to two Open R zones can be set in theuser data additional writing enable range 205. A location in whicheither of the above two types of R zones are not set in the user dataadditional writing enable range 205, i.e., a location in which the userdata is reserved to record the user data (as either of the above twotypes of R zones), is referred to as an unspecified R zone (Invisible RZone). In the case where the user data is fully recorded in the userdata additional writing enable range 205, and then, no data can beadded, this Invisible R zone does not exist.

Up to 254-th R zone position information is recorded in an RMD field 7.The “whole R zone number information” first recorded in the RMD field 7denotes a total number totalizing the number of Invisible R Zonelogically established in the user data additional writing enable range205, Open R Zones and the number of Complete R Zones. Next, the numberinformation on the first Open R zone and the number information on thesecond Open R zones are recorded. As described previously, the user dataadditional writing enable range 205 cannot have three or more Open Rzones, and thus, “1” or “0” is recorded (in the case where the first orsecond Open R zone does not exist). Next, the start position informationand the end position information on the first Complete R zone aredescribed in physical sector numbers. Then, the second to 254th startposition information and end position information are sequentiallydescribed in the physical sector numbers.

In an RMD field 8 and subsequent, the 255-th and subsequent startposition information and end position information are sequentiallydescribed in the physical sector numbers, and a maximum of RMD fields 15(a maximum of 2047 Complete R zones) can be described according to thenumber of Complete R Zones.

FIGS. 51 and 52 each show another embodiment with respect to a datastructure in the recording management data RMD shown in FIGS. 44 to 49.In the embodiment shown in FIGS. 51 and 52, up to 128 bordered areasBRDAs can be set on one write-once type information storage medium.Therefore, the start position information on the first to 128 border outareas BRDOs is recorded in the RMD field 3. In the case where (128 orless) bordered areas BRDAs are set midway, “00h” is set as the startposition information on the subsequent border out areas BRDOs. In thismanner, it is possible to identify how many bordered areas BRDAs are seton the write-once information storage medium merely by checking to wherethe start position information on the border out areas BRDOs arerecorded in the RMD field 3.

In the embodiment shown in FIGS. 51 and 52, up to 128 extended recordingmanagement zones RMZs can be set on one write-once information storagemedium. As described above, there are two types of extended recordingmanagement zones RMZs such as:

1) an extended recording management zone RMZ set in the border-in areaBRDI; and

2) an extended recording management zone RMZ set by utilizing an R zone.

In the embodiment shown in FIGS. 51 and 52, without discriminating thesetwo types of RMZ zones, they are managed by recoding a pair of the startposition information on the extended recording management zone RMZ(indicated by the physical sector number) and size information (numberinformation on occupying physical sectors) in the RMD field 3. In theembodiment shown in FIGS. 51 and 52, although there has been recorded:information on a pair of the start position information (indicated bythe physical sector number) and size information (number information onoccupying physical sectors) on the extended recording management zoneRMZ, a set of the start position (indicated by the physical sectornumber) and the end position information (indicated by the physicalsector number) on the extended recording management zone RMZ may berecorded without being limited thereto. In the embodiment shown in FIGS.51 and 52, although the extended recording management zones RMZ numbershave been assigned in order set on the write-once type informationstorage medium, the extended recording management data zone RMZ numberscan be assigned in order from the lowest physical sector number as astart position without being limited thereto. Then, the latest recordingmanagement data RMD is recorded, a currently used recording managementzone (which is open to enable additional writing of RMD) is specified bythe number of this extended recording management zone RMZ. Therefore,the information recording/reproducing apparatus or the informationreproducing apparatus identifies the start position information on thecurrently used (opened so that the RMZ can be additionally recorded)recording management zone based on these items of information, andcarries out identification of which one is the latest recordingmanagement data RMD from the identified information.

Even if the extended recording management zone is arranged to bedistributed onto the write-once type information storage medium, theinformation recording/reproducing apparatus or information reproducingapparatus can easily carry out identification of which one is the latestrecording management data RMD by taking a data structure shown in FIGS.51 and 52 each. Based on these items of information; the start positioninformation on the currently used (opened) recording management zone isidentified; and the location is accessed to identify to where therecording management data RMD has already been recorded. In this manner,the information recording/reproducing apparatus or the informationreproducing apparatus can easily identify to where the updated latestrecording management data may be recorded.

In the case where 2) an extended recording management zone RMZ set byutilizing an R zone has been set, one whole R zone corresponds to oneextended recording management zone RMZ. Thus, the physical sector numberindicating the corresponding start position of the extended recordingmanagement zone RMZ described in the RMD field 3 coincides with thecorresponding physical sector number indicating the start position ofthe R zone described in the RMD fields 4 to 21.

In the embodiment shown in FIGS. 51 and 52, up to 4606 (4351+255) Rzones can be set in one write-once type information storage medium. Thisset R zone position information is recorded in the RMD field 4 to 21.The start position information on each R zone is displayed by theinformation on the physical sector number, and the physical sectornumbers LRAs (Last Recorded Addresses) indicating the end recordingposition in each R zone are recorded in pair. Although the R zonesdescribed in the recording management data RMD are set in order ofsetting R zones in the embodiment shown in FIGS. 51 and 52, these zonescan be set in order from the lowest physical sector number indicatingthe start position information without being limited thereto.

In the case where R zone setting of the corresponding number is notprovided, “00h” is recorded in this field. Number information oninvisible R zone is described in the RMD field 4. This numberinformation on invisible R zone is indicated by a total number of thenumber of invisible R zones (zones in which area reserved for datarecording is not made in data area DTA); the number of open type R zones(zones each having an unrecorded area in which additional writing can becarried out); and the number of complete type R zones (R zones which arealready complete and which does not have an unrecorded area in whichadditional writing can be carried out). In the embodiment shown in FIGS.51 and 52, it is possible to set up to two Open R zones in whichadditional writing can be carried out. In this way, by setting up to twoOpen R zones, it is possible to record video image information or audioinformation for which continuous recording or continuous reproductionmust be guaranteed in one Open R zone, and then, separately recordmanagement information relevant to the video image information or audioinformation; general information used by a personal computer or thelike; or file system management information in the remaining one Open Rzone. Namely, it is possible to separately record plural items ofinformation in another Open R zone according to type of user data to berecorded. This results in improved convenience in recording orreproducing AV information (video image information or audioinformation).

In the embodiment shown in FIGS. 51 and 52, which R zone is an Open Rzone is specified by the R zone allocation numbers arranged in the RMDfields 4 to 21. That is, the R zones are specified by the correspondingR zone number to the first and second Open R zones. A search can beeasily made for the Open R zone by taking such a data structure. In thecase where no Open R zone exists, “00h” is recorded in that field. Inthe present embodiment, the end position of an R zone coincides with theend recording position in the Complete R zone, the end position of the Rzone and the last recording position LRA in the R zone are differentfrom each other in the Open T zone. On the way of additionally writinguser information in the Open R zone (at a state that precedes completionof additional writing of the recording management data RMD to beupdated), the end recording position and a recording position at whichadditional writing can be further carried out are shifted. However,after an additional writing process of user information has completed,after completing the additional writing process of the latest recordingmanagement data RMD to be recorded, the end recording position and anend recording position at which additional writing can be furthercarried out coincide with each other. Therefore, after completing theadditional writing process of the latest recording management data RMDto be updated, in the case where additional writing of new user data iscarried out, the control unit 143 in the informationrecording/reproducing apparatus shown in FIG. 11 carries out processingin accordance with procedures for:

1) checking a number of an R zone which corresponds to the Open R zonedescribed in the RMD field 4;

2) checking a physical sector number indicating an end recordingposition in the Open R zone described in each of the RMD fields 4 to 21to identify an end recording position at which additional writing can becarried out; and

3) starting additional writing from the above identified end recordingposition NWA at which additional writing can be carried out.

In this manner, a new additional writing start position is identified byutilizing Open R zone information in the RMD field 4, thereby making itpossible to sample a new additional writing start position simply andspeedily.

FIG. 53 shows a data structure in an RMD field in the embodiment shownin FIGS. 51 and 52. As compared with the embodiment shown in FIGS. 44 to49, there are added: address information on a location in whichrecording condition adjustment has been made in the inner drive testzone DRTZ (which belongs to the data lead-in area DTLDI); and addressinformation on a location in which recording condition adjustment hasbeen made in the outer drive test zone DRTZ (which belongs to the datalead-out area DTLDO). These items of information are described in thephysical segment block address numbers. Further, in the embodiment shownin FIG. 53, there are added: information relating to a method forautomatically adjusting a recording condition (running OPC); and the endDSV (Digital Sum Value) value at the end of recording (see FIG. 113described later).

Now, a description will be given below with respect to a method formaking a search for a position of a location lastly recorded in awrite-once type information recording medium having information recordedat multiple borders in the present embodiment.

FIG. 93A schematically shows a method for making a search for a locationlastly recorded in an information recording/reproducing apparatus. FIG.94 is a flow chart showing a specific processing operation. In addition,FIG. 93B schematically shows a method for making a search for a locationlastly recorded in an information reproducing apparatus. FIG. 95 is aflow chart showing the relevant processing operation. In FIGS. 93A and93B, a jump processing operation for access is indicated by the dashedline, and an actual information reading location is indicated by thesolid line. The locations for carrying out actual processing operationsin the information recording/reproducing apparatus or the informationreproducing apparatus are an information recording/reproducing section141 and a control section 143 shown in FIG. 11. A PR equalizing circuit130, a PLL circuit 174, an A/D converter 169, a sync code positiondetecting section 145, a data ID section and an IED section extractingsection 171, an error check section 172 of the data ID section or thelike function at the time of information reproduction. An optical headas shown in FIG. 90A or FIG. 91A, for example, exists in the informationrecording/reproducing section 141, and a focusing spot of the laserlight beam 1117 focused by means of an objective lens 1128 moves on aninformation storage medium 1101, and carries out a jump processingoperation or an information read processing operation for access. Inaddition, a series of operations shown below is controlled and managedby means of the control section 143.

As shown in FIG. 93A, in the information recording/reproducingapparatus, physical format information PFI or the like is recorded in asystem lead-in area SYLDI. In a data lead-in area DTLDI, an RMDduplication zone RDZ, a recording position management zone RMZ, an Rphysical information zone R-PFIZ, and a reference code recording zoneRCZ are allocated sequentially from its inner periphery. In theembodiments shown in FIGS. 93A and 93B, three border-in regions BRDA #1to #3 exist.

When the write-once type information recording medium having informationrecorded therein in the form shown in FIGS. 93A and 93B is inserted intothe information recording/reproducing apparatus or the informationreproducing apparatus, the information recording/reproducing apparatusor the information reproducing apparatus makes a search for a physicalsector number or a physical segment number (PSN) indicating a lastlyrecorded position. FIGS. 93A and 93B each show a method for making asearch for the physical sector number or physical segment number (PSN)indicating the lastly recorded position. The informationrecording/reproducing apparatus shown in FIG. 93A first reproducesinformation contained in a system lead-in area SYLDI (#31 shown in FIG.94). Physical format information PFI is recorded in the system lead-inarea SYLDI, and thus, the physical format information PFI is firstreproduced. Next, an access is provided to the RMD duplication zone RDZthat exists in the data lead-in area DTLDI (#32 shown in FIG. 94), and asearch is made for the recording position management data RMD lastlyrecorded in the area (#33 shown in FIG. 94).

In the “last recording position management data RMD#B in thecorresponding RMZ” having carried out reproduction in #33 (refer to FIG.36B), physical sector number information indicating a start position ofan n-th extended recording position management zone RMZ is recorded asshown in RMD field number 3 shown in FIG. 51, thereby readinginformation on the physical sector number or the physical segment number(PSN) indicating the start position of the extended recording positionmanagement zone RMZ lastly set from this information (#34 shown in FIG.94). Next, the information recording/reproducing apparatus provides anaccess to a position of the extended recording position management zoneRMZ which has been lastly set, and makes a search for the recordingposition management data RMD that has been lastly recorded therein.

The information on the physical sector number or the physical segmentnumber (PSN) indicating the lastly recorded position in the write-onceinformation storage medium shown in the present embodiment can beobtained from the information contained in the “recording positionmanagement data RDM lastly recorded in the extended recording positionmanagement zone RMZ that has been lastly set”. That is, the recordingposition management data RMD includes end position information on ann-th “complete type R zone (Complete R zone)” described in RMD field 7or later shown in FIG. 49 or information on “physical sector number LRArepresenting the last recording position in the n-th R zone” shown inFIG. 52, thereby reading the physical sector number or physical segmentnumber (PSN) in the lastly recorded location from the inside of therecording position management data RMD (refer to RMD#3 shown in FIG.36B, for example) that has been lastly recorded in the lastly setextended RMZ, at #35 shown in FIG. 94, and making it possible to knowthe lastly recorded location from a result of the reading.

The information reproducing apparatus uses a DPD (Differential PhaseDetection) technique instead of a Push-Pull technique for track shiftdetection, and thus, tracking control can be carried out only in an areain which an emboss pit or a recording mark exists. Thus, the informationreproducing apparatus cannot provide an access to an unrecorded area ofthe write-once type information storage medium, making it impossible tocarry out reproduction in the RMD duplication zone RDZ that includes theunrecorded area as shown in FIG. 93B. Thus, the recording positionmanagement data RMD recorded therein cannot be reproduced. Instead, theinformation reproducing apparatus can reproduce physical formatinformation PFI, R physical information zone R-PFIZ, and updatedphysical format information UPFI. Thus, a search can be made for thelastly recorded location in accordance with the method shown in FIG.93B.

The information reproducing apparatus carries out informationreproduction (#41 shown in FIG. 95) in a system lead-in area SYLDI, andthen, reads the last positional information on the existing informationdata recorded in the R physical information zone R-PFIZ (information on“physical sector number indicating the lastly recorded location in thelast R zone in the corresponding border-in area”) (#42 shown in FIG.95). As a result, as shown in FIG. 93B, it is possible to know the lastlocation of the bordered area BRDA #1. In addition, after checking aposition of border-out BRDO allocated immediately after the lastlocation, it is possible to read information on the updated physicalformat UPFI recorded in border-in BRDI recorded immediately after thechecked position.

Instead of the foregoing method utilizing “physical sector numberindicating the lastly recorded location in the last R zone in thecorresponding border-in area” described in FIG. 115, an access may beprovided to the start position of border-out BRDO by using informationon “physical sector number PSN indicating a start position of a borderzone” described in the 256th to 263rd bytes in FIG. 114 (this startposition denotes the start position of border-out BRDO, as is evidentfrom FIG. 39C).

Next, an access is provided to the last position of recorded data, at#43 of FIG. 95, thereby reading the last position information (FIG. 115)on the recorded data contained in updated physical format informationUFPI. A processing operation of reading “information on the lastlyrecorded physical sector number or physical segment number (PSN)”recorded in the updated physical format information, and then, providingaccess to the lastly recorded physical sector number or physical segmentnumber (PSN) based on the read information is repeated until the lastlyrecorded physical sector number PSN in the last R zone has been reached.That is, it is determined that a location of reading information, thelocation having been reached after access is really the lastly recordedposition in the last R zone (#44 shown in FIG. 95). In the case wherethe determination result is negative, the above-described accessprocessing operation is repeated. As in R physical information zoneR-PFIZ, in the present embodiment, a search may be made for recordingposition of the updated physical format information UPFI recorded in aborder zone (border-in BRDI) by utilizing information on the updatedphysical sector number or physical segment number (PSN) indicating astart position of a border zone” in the updated physical formatinformation UPFI.

When the position of the physical sector number (or physical segmentnumber) lastly recorded in the last R zone is found, the informationreproducing apparatus carries out reproduction from the immediatelypreceding position of border-out (#45 shown in FIG. 95). Then, at #46,the lastly recorded position is reached while the inside of the lastbordered area BRDA is serially reproduced from the start. Then, a checkof the last border-out BRDO is made. In the write-once type informationstorage medium according to the present embodiment, at the outside ofthe above last border-out BRDO, an unrecorded area in which no recordingmark is recorded follows up to the position of data lead-out DTLDO. Inthe information reproducing apparatus, no tracking is carried out in anunrecorded area on the write-once type information recording medium, andthe information on the physical sector number PSN is not recorded, thusmaking it impossible to carry out reproduction at a position followingthe last border-out BRDO. Thus, when the last border-out position hasbeen reached, an access processing operation and a continuousreproducing processing operation terminate.

Referring to FIG. 116, a description will be given with respect to atiming (updating condition) of updating the contents of information inthe recording position management data RMD shown in FIGS. 44 to 48 and51 to 53. There exist five types of conditions for updating informationon the recording position management data RMD.

(Condition 1a) In the case where medium status information (Disc states)in RMD field “0” (refer to FIG. 44) is changed:

An update processing operation of the recording position management dataRMD is not carried out at the time of recording of a terminator (“endposition information” recorded at the rear (outer periphery side) of thelastly recorded border-out BRDO).

(Condition 1b) In the case where an inner test zone address or an outertest zone address (Inner or outer test zone address) specified in RMDfield “1” is changed:

(Condition 2) In the case where border-out BRDO start positioninformation (Start Physical Sector Number of Border-out area) or open(write-once possible) recording position management zone RMZ number(open Extended RMZ number), specified in RMD field “3” (refer to FIG.51) is changed:

(Condition 3) In the case where information on any one of the followingitems is changed in RMD filed “4” (refer to FIG. 52):

1) A total number of unspecified R zone number, open type R zone number,and complete type R zone or invisible R zone number (Invisible R Zonenumber)

2) First open type R zone number information (First Open R Zone number)

3) Second open type R zone number information (Second R Zone number)

In the present embodiment, during a period in which a series ofinformation recording operations are made for a write-once typeinformation storage medium such as HD DVD-R (by means of a disc drive),there is no need for updating RMD. For example, in the case of recordingvideo image information, there is a need for continuous recording to beguaranteed. If access control of up to a position of recordingmanagement data RMD is made in order to update recording positionmanagement data RMD in the middle of video image information recording(image recording), continuous recording is not guaranteed becauserecording of video image information is interrupted. Therefore, theupdate of RMD is generally carried out after the video image recordingis terminated. If a series of video image information recordingoperations continues for an excessively long period of time, thelocation lastly recorded on the write-once type information storagemedium at the current time point and the last position informationcontained in the recording position management data RMD that has beenalready recorded in the write-once type information storage medium willbe significantly shifted. At this time, in the case where an abnormalphenomenon in the middle of continuous recording occurs, and then, theinformation recording/reproducing apparatus (disc drive) is forciblyterminated, discrepancy between “the last position information containedin the recording position management data RMD” and a recording positionimmediately before forcible termination becomes excessively large. As aresult, there occurs a danger that data recovery conforming to arecording position immediately before forcible termination with respectto the “last position information contained in the recording positionmanagement data RMD” becomes difficult. Therefore, in the presentembodiment, the following update condition is further added.

(Condition 4) (Information on the recording position management data RMDis updated) in the case where discrepancy (a differential result of“PSN-LRA”) between a “physical sector number LRA indicating the lastrecording position in an R zone” recorded in the latest recordingposition management data RMD and a “physical sector number PSN in thelastly recorded location in a R zone at the current time point” whichserially changes during continuous recording exceeds 8192:

However, in the above-described “condition 1b)” or “(condition 4)”, noupdating is carried out in the case where the size of an unrecordedlocation in the recording position management zone RMZ (reserved area273 shown in FIG. 38B) is equal to or smaller than 4 physical segmentblocks (4×64 KB).

Now, a description will be given with respect to an extended recordingposition management zone. As setting locations of the recording positionmanagement zone, the present embodiment defines the following threetypes.

1) Recording position management zone RMZ (L-RMZ) in data lead-in areaDTLDI

As is evident from FIG. 39B, in the present embodiment, part of theinside of the data lead-in area DTLDI is used for the border-in BRDIcorresponding to the first bordered area. Therefore, the recodingposition management zone RMZ to be recorded in the border-in BRDI thatcorresponds to the first bordered area is preset in the data lead-inarea DTLDI, as shown in FIG. 36A. In the internal structure of thisrecording position management zone RMZ, serial recording positionmanagement data RMD can be written once by 64 Kbytes (by 1 physicalsegment block size).

2) Recording position management zone RMZ (B-RMZ) in border-in BRDI

In the write-once type information storage medium according to thepresent embodiment, before reproducing recorded information by areproduction only apparatus, there is a need for a border closeprocessing operation as shown in FIG. 99. In the case where newinformation is recorded after a border has been closed once, there is aneed for setting a new bordered area BRDA. The border-in BRDI is set ata position preceding this new bordered area BRDA. The unrecorded area inthe latest recording position management zone is closed at the stage ofborder close processing operation (reserved area 273 shown in FIG. 36B).Thus, there is a need for setting a new area (recording positionmanagement zone RMZ) for recording the recording position managementdata RMD that indicates a position of the information recorded in a newbordered area BRDA. The present embodiment, as shown in FIG. 39D, isfeatured in that a recording position management zone RMZ is set in thenewly set border-in BRDI. The internal structure of the recordingposition management zone RMZ in this border zone has a structure that iscompletely identical to the “recording position management zone RMZ(L-RMZ) that corresponds to the first bordered area”. In addition, theinformation contained in the recording position management data RMDrecorded in this area is recorded together with recording positionmanagement information relating to the data recorded in the precedingbordered area BRDA as well as the recording position management datarelating to the data recorded in the corresponding bordered area BRDA.

3) Recording position management zone RMZ (U-RMZ) in bordered area BRDA

RMZ in border-in BRDI (B-RMZ), shown in the item (2) cannot be setunless a new bordered area BRDA is set. In addition, the size of thefirst bordered area management zone RMZ (L-RMZ) shown in the item (1)(FIG. 38B) is finite, a reserved area 273 is depleted whileadditional-writing is repeated, and new recording position managementdata RMD cannot be written. In order to solve the above-describedproblem, in the present embodiment, an R zone for recoding a recordingposition management zone RMZ is newly provided in a bordered area BRDAso as to enable further addition. That is, there exists a specific Rzone in which the recording position management zone RMZ (U-RMZ) in thebordered area BRDA” is set.

In addition, without being limited to a case of reducing the remainingsize of an unrecorded area (reserved area 273) in the first borderedarea management zone RMZ (L-RMZ), the present embodiment is featured inthat, in the case of reducing the remaining size of the unrecorded area(reserved area 273) in the “recording position management zone RMZ(B-RMZ) in the border-in BRDI” and in the “recording position managementzone RMZ (U-RMZ) in the bordered area BRDA” that has already been set,the above-described “recording position management zone RMZ (U-RMZ) inthe bordered area BRDA” can be set.

The contents of information recorded in the recording positionmanagement zone RMZ (U-RMZ) in this bordered area BRDA have a structurethat is completely identical to that in the recording positionmanagement zone RMZ (L-RMZ) in the data lead-in area DTLDI shown in FIG.36B. In addition, the information contained in the recoding positionmanagement data RMD recorded in this area is recorded together withrecording position management information relating to the data recordedin the preceding bordered area BRDA as well as the recoding positionmanagement data relating to the data recorded in the correspondingbordered area BRDA.

Among the variety of recording position management zones RMZ describedabove,

1) A position of the recording position management zone RMZ (L-RMZ) inthe data lead-in area DTLDI is preset before recording user data.

However, in the present embodiment,

2) A recording position management zone RMZ (B-RMZ) in the border-inBRDI; and

3) A recording position management zone RMZ (U-RMZ) in the bordered areaBRDA

are properly set (extensively provided) by the informationrecording/reproducing apparatus in accordance with a user data recording(additional write) state, and thus, these zones are referred to as“extended (type) recording position management zones RMZ”.

A method for setting a recording position management zone RMZ in theabove-described bordered area BRDA is shown in FIGS. 96A to 96C, and itsflow chart is shown in FIG. 97. The numbers from items (a) to (c) shownin FIG. 97 correspond to FIGS. 96A to 96C.

In the case where an unrecorded area in a currently used recordingposition management zone RMZ (reserved area 273 shown in FIG. 38B) isequal to or smaller than a physical sector block (15×64 KB), the settingof the recording position management zone RMZ (U-RMZ) in the borderedarea BRDA can be provided. The size of the recording position managementzone RMZ in the bordered area BRDA at the time of setting (U-RMZ) isdefined as the size (128×64 KB) of 128 physical segment blocks, and thissize is defined as an R zone used exclusively for the recording positionmanagement zone RMZ.

If the size of an unrecorded area in the “recording position managementzone L-RMZ corresponding to the first bordered area” shown in FIG. 96Ais equal to or smaller than 15 physical segment blocks, a controlsection 143 shown in FIG. 11 senses that the inside of the existingrecording position management zone L-RMZ is almost full (#51 shown inFIG. 97). When the sensing is carried out, an incomplete type R zone 42shown in FIG. 96A is closed, and the current zone is changed to acomplete R zone (#52 shown in FIG. 97). Next, as shown in FIG. 96B, anew exclusive R zone is set, and its inside is defined as a recordingposition management zone U-RMZ which exists in a bordered area BRDA (#53shown in FIG. 97). As a result, while the incomplete type R zone 42shown in FIG. 96A is divided into the complete type R zone 43 and therecording position management zone U-RMZ that exists in the borderedarea BRDA, the remaining area is set to an unspecified R zone 44, asshown in FIG. 96B (#54 shown in FIG. 97).

As a result of a series of processing operations described above, acurrently used recording position management zone RMZ moves from therecording position management zone RMZ (L-RMZ) that corresponds to thefirst bordered area to the recording position management zone U-RMZ thatexists in the bordered area BRDA. Thus, as a close processing operationin the recording position management zone RMZ (L-RMZ) that correspondsto the first bordered area, as shown in FIG. 96C, an unrecorded area inthe recording position management zone L-RMZ that corresponds to thefirst bordered area is repeatedly recorded with the latest recordingposition management data RMD47, and the unrecorded area is eliminated(#55 shown in FIG. 97). Concurrently with a change in position of therecording position management zone RMZ, at #56 of FIG. 97, copyinformation 48 contained in the latest recording management data RMD47is recorded in the RMD duplication zone RMZ (FIG. 96C).

In the write-once type information storage medium according to thepresent embodiment, it becomes possible to set the above-described threetypes of recording position management zones RMZ, and thus, the presenceof a very large number of recording position management zones RMZ isallowed on one write-once type information recording/storage medium.Therefore, in the present embodiment, for the purpose of facilitating asearch for the latest recording position management data RMD recordinglocation, the following processing operations are made:

1) In the case of newly setting a recording position management zoneRMZ, the latest recording position management data RMD is overwritten inthe recording position management zone RMZ that has been used up to nowso as not to allow an unrecorded area to exist in the recording positionmanagement zone RMZ that has been used up to now. In this manner, itbecomes possible to identify whether a recording position managementzone is currently used or is set in a new location.

2) Every time a recording position management zone RMZ is newly set,copy information 48 on the latest recording position management data RMDis recorded in an RMD duplication zone RMZ. In this manner, a search iseasily made for the currently used recording position management zoneRMZ location.

As shown in FIG. 96C, the presence of a large number of unrecorded areasis allowed in the write-once type information storage medium accordingto the present embodiment. However, in a reproduction only apparatus, aDPD (Differential Phase Detection) technique is used for track shiftdetection, thus disabling tracking in an unrecorded area. Therefore,before reproducing the above described write-once type informationstorage medium by the reproduction only apparatus, there is a need forcarrying out a border close processing operation shown in FIG. 99 sothat an unrecorded area does not exist.

Now, a border close processing method will be described here.

FIG. 98A shows a data structure on a write-once type information storagemedium in the middle of once-writing. In this state, unrecorded areas54, 55, and 56 exist, thus disabling reproduction at the informationreproducing apparatus.

FIG. 98B shows a data structure in a state in which reproduction can becarried out by the information reproducing apparatus after border closeprocessing operation has been made.

The state shown in FIG. 98A is changed to the state shown in FIG. 98B bycarrying out the border close processing operation shown in FIG. 99.Specific procedures for carrying out the border close processingoperation will be described below with reference to the flow chart shownin FIG. 99. Upon the receipt of a border close request (#61), theincomplete type R zone 42 is changed to a complete type R zone in whichthe lastly recorded position therein is defined as a final position(#62). Next, at #63, border-out BRDO is set immediately following alocation that has been a recorded area of the incomplete type R zone 42.Further, at #64, the latest recording position management data RMD isrepeatedly recorded and fully embedded in an unrecorded area 54 in therecording position management zone U-RMZ #3 that exists in the borderedarea BRDA. Next, at #65, copy information on the latest recordingposition management data RMD recorded in #64 is recorded in the RMDduplication zone RMZ. Further, predetermined data is recorded inunrecorded areas 55 and 56 in border-in BRDI so that an unrecorded areadoes not exist (#66). As a result, as shown in FIG. 98B, all the areasup to border-out BRDO in the data area DTA are embedded with recordeddata.

FIG. 56 shows an outline of converting procedures for, after an ECCblock is configured of a data frame structure in which user data inunits of 2048 bytes has been recorded, and then, sync codes have beenadded, forming a physical sector structure to be recorded in aninformation storage medium. These converting procedures are employed incommon for a read-only type information storage medium, a write-oncetype information storage medium, and a rewritable-type informationstorage medium. According to each converting stage, a data frame, ascrambled frame, a recording flame, or recorded data field are defined.The data frame is a location in which user data is recorded. This frameis composed of: main data consisting of 2048 types; a four-type data ID;a two-byte ID error detecting code (IED); a six-byte reserved bytes(RSV); and a four-byte error detecting code (EDC). First, after an IED(ID error detecting code) has been added to a data ID described later,the 6-byte reserved byte and main data consisting of 2048 bytes and inwhich the user data is recorded are added. Then, an error detecting code(EDC) is added. Then, scrambling relevant to the main data is executed.Here, a Cross Reed-Solomon Error Correction Code is applied to thesescrambled 32 data frames (scrambled frames), and an ECC encodeprocessing operation is executed. In this manner, a recording frame isconfigured. This recording frame includes a parity of outer-code (PO)and a parity of inner-code (PI). The PO and PI each are error correctingcodes produced with respect ECC blocks, each of which is formed of 32scrambled frames. The recording frame, as described previously, issubjected to ETM (Eight to Twelve Modulation) for converting eight databits to 12-channel bits. Then, a sync code SYNC is added to thebeginning on a 91 by 91 bytes basis, and 32 physical sectors are formed.As described in the lower right frame shown in FIG. 56, the presentembodiment is featured in that one error correcting unit (ECC block) iscomposed of 32 sectors. As described later, the numbers “0” to 31” ineach frame shown in FIG. 60 or 61 indicate the numbers of physicalsectors, respectively, and a structure is provided to ensure that onelarge ECC block is composed of a total of 32 physical sectors. In anext-generation DVD, even in the case where a scratch whose extent isidentical to that of a current-generation DVD adheres to an informationstorage medium surface, it is required to enable reproduction of preciseinformation by an error correction processing operation. In the presentembodiment, recording density has been improved for the achievement ofhigh capacity. As a result, in the case where a conventional one ECCblock=16 sectors, a length of a physical scratch which can be correctedby error correction is reduced as compared with a conventional DVD. Asin the present embodiment, there is attained advantageous effect thatone ECC block is composed of 32 sectors, thereby making it possible toincrease an allowable length of a scratch on the information storagemedium surface for which error correction can be carried out and toensure compatibility/format continuity of a current DVD ECC blockstructure.

FIG. 57 shows a structure in a data frame. One data frame is 2064 bytesconsisting of 172 bytes×2×6 rows, and includes main data of 2048 bytes.IED is an acronym for IE Error Detection Code, and denotes a reservedarea for enabling setting of information in the future. EDC is anacronym for Error Detection Code, and denotes an additional code forerror detection of a whole data frame.

FIGS. 50A to 50D show a data structure in a data ID shown in FIG. 57.The data ID is composed of items of information on data frames 921 and922. The data frame number indicates a physical sector number 922 of thecorresponding data frame.

The data frame information 921 is composed of the following items ofinformation.

Format Type 931

0b: This indicates CLV.

1b: This indicates zone configuration

Tracking Method 932

0b: This is pit-compatible and uses a DPD (Differential Phase Detect)technique in the present embodiment.

1b: This is pre-groove compatible and uses a push-pull technique or aDPP (Differential Push-Pull) technique.

Recording Film Reflection Factor 933

0b: 40% or more

1b: 40% or less

Recording Type Information 934

0b: General data

1b: Real time data (Audio Video data)

Area Type Information 935

00b: Data area DTA

01b: System lead-in area SYLDI or data lead-in area DTLDI

10b: Data lead-out area DTLDO or system lead-out area SYLDO

Data Type Information 936

0b: Read-only data

1b: Rewritable data

Layer Number 937

0b: Layer 0

1b: Layer 1

FIG. 58A shows an example of default values assigned to a feedback shiftregister when a frame after scrambled is produced. FIG. 58B shows acircuit configuration of the feedback shift register for producingscrambled bytes. The values of r7 (MSB) to r0 (LSB) are used as scramblebytes while they are shifted by 8 by 8 bit basis. As shown in FIG. 58A,16 types of preset values are provided in the present embodiment. Thedefault preset numbers shown in FIG. 58A are equal to 4 bits of data ID(b7 (MSB) to b4 (LSB)). When data frame scrambling is started, thedefault values of r14 to r0 must be set to the default preset values ina table shown in FIG. 58A. The same default preset value is used for 16continuous data frames. Next, the default preset values are changed, andthe changed same preset value is used for the 16 continuous data frames.

The least significant eight bits of the default values of r7 to r0 aresampled as a scramble byte S0. Then, eight-bit shifting is carried out,and the scrambled byte is then sampled. Such an operation is repeated2047 times.

FIG. 59 shows an ECC block structure in the present embodiment. The ECCblock is formed of 32 scrambled frames. 192 rows+16 rows are arranged ina vertical direction, and (172+10)×2 columns are arranged in ahorizontal direction. B_(0,0), B_(1,0), . . . are one byte,respectively. PO and PI are error correction codes, and an outer parityand an inner parity. In the present embodiment, an ECC block structureusing a multiple code is configured. That is, as error correctionadditional bits, a structure is provided such that, PI (Parity in) isadded in a “row” direction, and PO (Parity out) is added in a “column”direction. A high error correction capability using an erasurecorrection and a vertical and horizontal repetitive correction processcan be guaranteed by configuring such an ECC block structure using amultiple code. Unlike a conventional DVD ECC block structure, the ECCblock structure shown in FIG. 59 is featured in that two PIs are set inthe same “row”. That is, PI of 10-byte size described at the center inFIG. 59 is added to 172 bytes arranged at the left side. That is, forexample, 10-byte PI from B_(0,0) to B_(0,172) is added to 172-byte datafrom B_(0,0) to B_(0,171); and 10-byte PI from B_(1,172) to B_(1,181) isadded to 172-byte data from B_(1,0) to B_(1,171). The PI of 10-byte sizedescribed at the right end of FIG. 59 is added to 172 bytes arranged atthe center on the left side of the FIG. 59. That is, for example,10-byte PI from B_(0,354) to B_(0,363) are added to 172-byte data fromB_(0,182) to B_(0,353).

FIG. 60 shows an illustration of a frame arrangement after scrambled.Units of (6 rows×172 bytes) are handled as one frame after scrambled.That is, one ECC block is formed of 32 frames after scrambled. Further,this system handles a pair of (block 182 bytes×207 bytes). When L isassigned to the number of each frame after scrambled, in the left sideECC block, and R is assigned to the number of each frame after scrambledin the right side ECC block, the frames after scrambled are arranged asshown in FIG. 60. That is, the left and right frames after scrambledexist alternately at the left side block, and the frames after scrambledexist alternately at the right side block.

That is, the ECC block is formed of 32 frames after continuouslyscrambled. Lines of the left half of odd numbered sectors each areexchanged with those of the right half. 172×2 bytes×192 rows are equalto 172 bytes×12 rows×32 scrambled frames, and are obtained as a dataarea. 16-byte PO is added to form an outer code of RS (208, 192, 17) ineach 172×2 columns. 10-byte PI (RS (182, 172, 11)) is added to each208×2 rows in the left and right blocks. PI is added to a row of PO aswell. The numerals in frames indicate scrambled frame numbers, andsuffixes R and L denote the right half and the left half of thescrambled frame. The present embodiment is featured in that the samedata frame is arranged to be distributed in a plurality of small ECCblocks. Specifically, in the present embodiment, a large one ECC blockis composed of two small ECC blocks, and the same data frame arearranged to be alternately distributed into two small ECC blocks. As hasalready been described in FIG. 59, PI of 10-byte size described at thecenter is added to 172 bytes arranged at the left side, and PI of 10byte size described on the right end is added to 172 bytes arranged atthe center on the left side. Namely, the left side small ECC block iscomposed of continuous PI of 10 bytes from the left end of FIG. 59, andthe right side small ECC block is composed of 10 bytes at the right endfrom the central 172 bytes. The signs in each frame are set in responseto these blocks in FIG. 60. For example, “2-R” denotes which of a dataframe number and the left and right small ECC blocks one belongs to (forexample, one belongs to right side small ECC block in second dataframe). As described later, with respect to each of the finallyconfigured physical sectors, the data contained in the same physicalsector is also alternately arranged to be distributed into the left andright small ECC blocks (the columns of the left half in FIG. 61 areincluded in the left side small ECC block (small ECC block “A” on theleft side shown in FIG. 64), and the column of the right half areincluded in small ECC blocks (small ECC block B on the right side shownin FIG. 64).

Thus, when the same data frame is arranged to be distributed in aplurality of small ECC blocks, the reliability of recording data isimproved by improving an error correction capability of the datacontained in a physical sector (FIG. 61). For example, let us consider acase in which a track fails at the time of recording; the recorded datais overwritten; and data for one physical sector is damaged. In thepresent embodiment, the damaged data contained in one sector issubjected to error correction by using two small ECC blocks; a burden onerror correction in one ECC block is reduced; and error correction withbetter performance is guaranteed. In the present embodiment, even afterforming an ECC block, a structure is provided such that a data ID isarranged at the start position of each sector, thus making it possibleto check a data position at the time of access at a high speed.

FIG. 61 shows an illustration of a PO interleaving method. As shown inFIG. 61, 16 parities are distributed on one by one row basis. That is,16 parity rows are arranged on a one by one row basis with respect totwo recording frames placed. Therefore, a recording fame consisting of12 rows is obtained as 12 rows+1 row. After this row interleaving hasbeen carried out, 13 rows×182 bytes are referred to as a recordingframe. Therefore, an ECC block after row interleaved is formed of 32recording frames. In one recording, as described in FIG. 60, 6 rowsexist in each of the right side and left side blocks. POs are arrangedso as to be positioned in different rows between a left block (182×208bytes) and a right block (182×208 bytes). FIG. 61 shows one completetype ECC block. However, at the time of actual data reproduction, suchECC blocks continuously arrive at an error correction processingsection. In order to improve such an error correction processingcapability, there is employed an interleaving system as shown in FIG.61.

Referring to FIG. 61, a detailed description will be given with respectto a relationship from a structure in one data frame shown in FIG. 57 toa PO interleaving method shown in FIG. 61. FIG. 64 is an enlarged viewshowing, an upper side portion of an EC block structure afterPO-interleaved shown in FIG. 61, wherein allocation locations of dataID, IED, RSV, and EDC shown in FIG. 57 are explicitly indicated, therebyvisually identifying a series of conversion from FIGS. 57 to 61. “0-L”“0-R”, “1-R”, and “1-L” shown in FIG. 64 correspond to “0-L”, “0-R”,“1-R”, and “1-L” shown in FIG. 60, respectively. The “0-L” and “1-L”denote data obtained after only the main data has been scrambled withrespect to the left half shown in FIG. 57, that is, a set composed of172 bytes and six rows from the center line to the left side. Similarly,the “0-R” and “1-R” denote data obtained after only the main data hasbeen scrambled with respect to the right half shown in FIG. 57, that is,a set composed of 172 bytes and six rows from the center line to theright side. Therefore, as is evident from FIG. 57, data ID, IED, and RSVare arranged in order from the beginning of the first row (row 0) tobyte 12 of “0-L” and “1-L”. In FIG. 64, the centerline to the left sideconfigures the left side small ECC block “A”, and the centerline to theright side configures the right side small ECC block “B”. Therefore, asis evident from FIG. 64, data ID#1, data ID#2, IED#0, IED#2, RSV#0, andRSV#2 included in “0-L” and “2-L” are included in the left side smallECC block “A”. In FIG. 60, “0-L” and “2-L” are arranged at the leftside, and “0-R” and “2-E” are arranged at the right side. In contrast,“1-R” and “1-L” are arranged at the left and right sides, respectively.Data ID#1, IED#1, and RSV#1 are arranged from the beginning to byte 12of the first row in “1-L”. Thus, as a result of reversing the left andright allocations, as is evident from FIG. 64, data ID#1, IED#1, andRSV#1 included in “1-L” is configured in the right side small ECC block“B”. In the present embodiment, a combination of “0-L” and “0-R” in FIG.64 is referred to as a “0-th recording frame” and a combination of “1-L”and “1-R” is referred to as a “first recording frame”. The boundarybetween the recording frames are indicated by the bold characters shownin FIG. 64. As is evident from FIG. 64, data ID is arranged at thebeginning of each recording frame and PO and PI-L are arranged at theend of each recording frame. As shown in FIG. 64, the present embodimentis featured in that small ECC blocks in which data ID is included aredifferent from each other depending on the odd-numbered andeven-numbered recording frames, and data ID, IED, and RSV arealternately arranged in the left side and right side small ECC blocks“A” and “B” in accordance with continuous recording frames. The errorcorrection capability in one small ECC lock is limited, and errorcorrection is disabled with respect to a random error exceeding aspecific number or a burst error exceeding a specific length. Asdescribed above, data ID, IED, and RSV are alternately arranged in theleft side and right side small ECC blocks “A” and “B”, thereby making itpossible to improve the reliability of reproduction of data ID. That is,even if a defect on an information storage medium frequently occurs,disabling error correction of any of the small ECC blocks and disablingdecoding of data ID to which the faulty block belongs, data ID, IED, andRSV are alternately arranged in the left side and right side small ECCblocks “A” and “B”, thus enabling error correction in the other smallECC block and enabling decoding the remaining data ID. Because theaddress information contained in data ID continuously lasts, theinformation on data ID is used, enabling interpolation with respect tothe information on data ID which has not been successfully decoded. As aresult, the access reliability can be improved according to theembodiment shown in FIG. 64. The numbers parenthesized at the left sideof FIG. 64 denote row numbers in an ECC block after PO-interleaved. Inthe case where numbers are recorded in an information storage medium,row numbers are sequentially recorded from the left to the right. InFIG. 64, data ID intervals included in each recording frame are alwaysconstantly arranged, and thus, there is attained advantageous effectthat data ID position searching capability is improved.

A physical sector structure is shown in FIGS. 62A and 62B. FIG. 62Ashows an even numbered physical sector structure, and FIG. 62B show anodd numbered data structure. In FIGS. 62A and 62B, with respect to bothof an even recorded data field and an odd recorded data field, outerparity PO information shown in FIG. 61 is inserted into a sync data areacontained in the last 2 sync frames (i.e., in a portion at which thelast sync code is SY3 and a portion at which the immediately succeedingsync data and sync code is SY1; and a portion at which sync code is SY1and a portion at which the immediately succeeding sync data is arrangedin the sync data area shown in FIG. 61 wherein information of outerparity PO is inserted).

Part of the left side PO shown in FIG. 60 is inserted at the last twosync frames in the even recorded data field, and part of the right sidePO shown in FIG. 60 is inserted at the last two sync frames in the oddrecorded data field. As shown in FIG. 60, one ECC block is composed ofthe left and right small ECC blocks, respectively, and the data on POgroups alternately different depending on sectors (the data on PObelonging to left small ECC block or the data on PO belonging to rightsmall ECC block) is inserted.

The even numbered physical sector structure shown in FIG. 62A and theodd numbered data structure shown in FIG. 62B are divided into twosections at a center line. The left side “24+1092+24+1092 channel bitsare included in the left side small ECC block shown in FIG. 59 or 60,and the right side “24+1092+24+1092 channel bits are included in theright side small ECC block shown in FIG. 59 or 60. In the case where thephysical sector structure shown in FIGS. 62A and 62B is recorded in aninformation storage medium, this structure is serially recorded on oneby one column base. Therefore, for example, in the case where channelbit data on an even numbered physical sector structure shown in FIG. 62Ais recorded in an information storage medium, the data on 2232 channelbits first recorded is included in the left side small ECC block, andthe data on the 2232 channel bits recorded next is included in the rightside small EC block. Further, the data on 2232 channel bits recordednext is included in the left side small ECC block. In contrast, in thecase where the channel bit data on an odd numbered data structure shownin FIG. 62B is recorded in an information storage medium, the data on2232 channel bits first recorded is included in the right side small ECCblock, and the data on the 2232 channel bits recorded next is includedin the left side small EC block. Further, the data on 2232 channel bitsrecorded next is included in the right side small ECC block.

Thus, the present embodiment is featured in that the same physicalsector is alternately included in two small ECC blocks on a 2232 by 2322channel bit basis. In other words, a physical sector is formed in theshape such that the data included in the right side small ECC block andincluded in the left side small ECC block are alternately arranged to bedistributed on a 2232 by 2332 channel bit basis, and the formed physicalsector is recorded in an information storage medium.

As a result, there is attained advantageous effect that a structurestrong to a burst error can be provided. For example, let us consider astate in which a lengthwise scratch occurs in a circumferentialdirection of an information storage medium, and there occurs a bursterror which disables decoding of data exceeding 172 bytes. In this case,a burst error exceeding 172 bytes is arranged to be distributed in twosmall ECC blocks. Thus, a burden on error correction in one ECC block isreduced, and error correction with better performance is guaranteed.

The present embodiment is featured by, as shown in FIGS. 62A and 62B, adata structure in a physical sector is different from another dependingon whether or not the physical sector number of a physical sectorconfiguring one ECC block is an even number or an odd number. Namely,

1) Small ECC blocks (right side or left side) to which the first 2232channel bit data of a physical sector belongs are different from eachother; and

2) There is provided a structure in which data on a PO group alternatelydifferent from each other depending on sectors is inserted.

As a result, in order to guarantee a structure in which data ID isarranged at the start position of all the physical sectors even after anECC block has been configured, a data position check at the time ofaccess can be made at a high speed. In addition, POs which belong todifferent small ECC blocks are mixed and inserted into the same physicalsector, structurally simplifying a method employing a PO insertingmethod as shown in FIG. 61, facilitating information sampling on asector by sector manner after error correction processing in aninformation reproducing apparatus; and simplifying an ECC block dataassembling process in an information recording/reproducing apparatus.

In a method for specifically achieving the above contents, POinterleaving and inserting positions have different structures dependingon the left and right. Portions indicated by the narrow double linesshown in FIG. 61 or portions indicated by the narrow double line andshading indicate the PO interleaving and inserting positions. PO isinserted at the left end in an even numbered physical sector number orat the right end in an odd numbered physical sector number. By employingthis structure, even after an ECC block has configured, data ID isarranged at the start position of a physical sector, thus making itpossible to check a data position at the time of access at high speed.

FIG. 63 shows an embodiment of specific pattern contents from sync codes“SY0” to “SY3” shown in FIGS. 62A and 62B. Three states from State 0 toState 2 are provided in accordance with a modulation rule according tothe present embodiment (a detailed description will be given later).Four sync codes from SY0 to SY3 are set, and each code is selected fromthe left and right groups shown in FIG. 63 according to each state. In acurrent DVD specification, as a modulation system, there employed RLL(2, 10) of 8/16 modulation (8 bits are converted to 16 channel bits (aminimum value is 2 and a maximum value is 10 when Run Length Limit: d=2,k=10: “0” continuously lasts), four states from State 1 to State 4,i.e., eight types of sync codes from SY0 to SY7 are set. In comparison,in the present embodiment, types of sync codes are decreased. In aninformation recording/reproducing apparatus or an informationreproducing apparatus, at the time of information reproduction from aninformation storage medium, types of sync code is identified inaccordance with a pattern matching technique. As in the presentembodiment, by significantly decreasing types of sync codes, targetpatterns required for matching are decreased in number; a processingoperation required for pattern matching is simplified; and theprocessing efficiency is improved, making it possible to improve arecognition speed.

In FIG. 63, a bit (channel bit) indicated by “#” denotes a DSV (DigitalSum Value) control bit. As described later, the above DSV control bit isdetermined so as to suppress a DC component by means of a DSV controller(so as to make a value of DSM close to 0). The present embodiment isalso featured in that a polarity inversion channel bit “#” is includedin a sync code. There is attained advantageous effect that a value of“#” can be selected as “1” or “0” so that the DSV value is close to “0”in a macroscopic point of view, including both frame data fields (1092channel bit fields shown in FIGS. 62A and 62B) sandwiching the abovesync code, enabling DSV control from the macroscopic point of view.

As shown in FIG. 63, the sync codes in the present embodiment iscomposed of the sections below.

1) Sync Position Detecting Code Section

This section has a common pattern in all sync codes, and forms a fixedcode area. A sync code allocation position can be detected by detectingthis code. Specifically, this section denotes the last 18 channel bits“010000 000000 001001” in each sync code in FIG. 63.

2) Modulation Conversion Table Selector Code Section

This section forms part of a variable code area, and changes in responseto state number at the time of modulation. The first channel bit shownin FIG. 63 corresponds to this section. That is, in the case where oneof State 1 and State 2 is selected, the first channel bit is set to “1”in any of the codes from SY0 to SYY3. When State 0 is selected, thefirst channel bit of a sync code is set to “1”. However, as anexception, the first channel bit of SY3 in State 0 is set to “0” .

3) Sync Frame Position Identification Code Section

Part of a variable code area is composed of codes identifying types fromSY0 to SY3 in sync codes. The first to sixth channel bit section in eachsync code shown in FIG. 63 corresponds to this section. As describedlater, a relative position in the same sector can be detected from aconnection pattern of three by three sync codes continuously detected.

4) DC Suppressing Polarity Inversion Code Section

A channel bit at a position “#” shown in FIG. 63 corresponds to thissection. As described above, this bit is inverted or non-inverted,thereby making close to “0” the DSV value of a channel bit patternincluding the preceding and succeeding frame data.

In the present embodiment, 8/12 modulation (ETM: Eight to TwelveModulation), RLL (1, 10) is employed as a modulation method. That is,eight bits are converted to 12-cahnnel bits at the time of modulation,and a minimum value (d value) is set to 1, and a maximum value (k value)is set to 10 in a range such that the settings “0” after converted arecontinuous. In the present embodiment, although high density can beachieved more significantly than conventionally by setting d=1, it isdifficult to obtain a sufficiently large reproduction signal amplitudeat a site indicated by the mark indicating the highest density.

Therefore, as shown in FIG. 11, an information recording/reproducingapparatus according to the present embodiment has the PR equalizingcircuit 130 and the Viterbi decoder 156, and enables very stable signalreproduction by using a PRML (Partial Response Maximum Likelihood)technique. In addition, k=10 is set, and thus, there is no case in whicheleven or more “0” settings are continuous in the modulated generalchannel bit data. By utilizing this modulation rule, the above syncposition detecting code section has a pattern which hardly appears inthe modulated general channel bit data. That is, as shown in FIG. 63, inthe sync position detecting code section, 12 (=k+2) “0”s arecontinuously arranged. The information recording/reproducing apparatusor the information reproducing apparatus finds this section and detectsa position of the sync position detecting code section. In addition, if“0” continuously lasts too much, a bit shift error is likely to occur.Thus, in order to reduce this problem, in the sync position detectingcode section, a pattern having less continuous “0”s is arrangedimmediately after that portion. In the present embodiment, d=1, andthus, it is possible to set “101” as the corresponding pattern. However,as described above, a sufficiently large reproduction signal amplitudeis hardly obtained at a site of “101” (at a site indicating the highestdensity), and thus, “1001” is arranged instead, obtaining a pattern ofthe sync position detecting code section as shown in FIG. 63.

The present embodiment is featured in that, as shown in FIG. 63, 18channel bits at the back side in a sync code are independently used as(1) sync position detecting code section, and the front side 6 channelbits are used as (2) modulation conversion table selector code section;(3) sync frame position identification code section; or (4) DCsuppression polarity inversion code section. There is attainedadvantageous effect that in the sync codes, the sync position detectingcode section in item (1) is provided independently, thereby facilitatingsingle detection and enhancing sync position detecting precision; thecode sections in items (2) to (4) are used in common in the 6-channelbits, thereby reducing the data size of the whole sync codes (channelbit size); and a sync data occupying rate is increased, therebyimproving substantial data efficiency.

The present embodiment is featured in that, from among four types ofsync codes shown in FIG. 63, only SY0 is arranged at the first syncframe position in a sector, as shown in FIGS. 62A and 62B. Advantageouseffect thereof includes that the start position in a sector can beidentified immediately merely by detecting SY0, and the start positionsampling process in the sector is extremely simplified.

The present embodiment is also featured in that all of the combinationpatterns of three continuous sync codes are different from each other inthe same sector.

As shown in FIG. 63, a “13T” location in which 12 continuous “0s” areexist in a sync code pattern. In the present embodiment, running OPC forsetting an optimal recording condition is carried out by using this“13T” portions. That is, at this 13T portion, a recording condition isfinely changed in real time, and the optimal recording condition iscontrolled in a feedback manner while reproduction is carried out inreal time. In order to enable this feedback control, the presentembodiment is featured in that sync codes SY0 to SY3 allocated in FIG.62 are paired in order of allocation, and the “13T” portion in one ofthat pair is set to a recording mark (mark) and the “13T” portion in async code of the other one is spaced (an area between a recording markand a recording mark is provided). Therefore, in the present embodiment,polarity control of the “13T” portion is made as shown in FIG. 101. Thatis, the first sync code of a pair of sync codes which is allocated inconnection in a two by two code basis is utilized for DC suppressioncontrol, and the second sync code “13T” of the pair is set in invertedpolarity relevant to the preceding “13T”.

FIG. 101 is a flow chart showing specific procedures. At #71, setting ofa sync code starts. A value of “#” shown at FIG. 63 in a starting synccode of one pair is set to utilize DC suppression control, at #72. Thevalue of “#” is set to “1” or “0” so that an absolute value of DSV(Digital Sum Value) is close to “0”. Next, the polarity at the positionof “13T” is checked, and it is determined whether the position of “13T”is within a mark or above a space (#73). The flow waits for the secondsync code of such one pair (next sync code position) (#74 and #75). Inthe case where the position of “13T” in the starting sync code of suchone pair is within the mark, it is determined whether # bit in the synccode shown in FIG. 63 is set to “1” or “0” so that the position of “13T”in a next sync code (last sync code of one pair) is on a space. Inaddition, in the case where the position of “13T” in the first sync codeof one pair has been on a space, it is determined whether # bit in thesync code shown in FIG. 63 is set to “1” or “0” so that the position of“13T” in the next sync code (last sync code of one pair) is within themark (#77). Then, the flow waits for the next sync code (first sync codeof next pair) (#78), and the above-described processing operation isrepeated.

A detailed description will be given with respect to the patterncontents of a reference code recorded in the reference code recordingzone RCZ shown in FIGS. 35A to 35C. In a current DVD standard, an “8/16modulation” system for converting 8-bit data to 16-channel bits isemployed as a modulation system. As a pattern of a reference codeserving as a channel bit pattern recorded in an information storagemedium after modulated, there is employed a repetition pattern“00100000100000010010000010000001”. In comparison with this pattern, inthe present embodiment, ETM modulation for modulating 8-bit data into12-channel bits is used as shown in FIGS. 32 to 34, providing an RLL (1,10) run length restriction. In addition, the PRML technique is employedfor signal reproduction from the data lead-in area DTLDI, data area DTA,data lead-out area DTLDO, and middle area MDA. Therefore, there is aneed for setting the above described modulation rule and a pattern of areference code optimal for PRML detection. In accordance with the RLL(1, 10) run length restriction, a minimum value of continuous “0”settings is “d=1”, and is a repetition pattern of “10101010”. Assumingthat a distance from a code “0” to the next adjacent code is “T”, adistance relevant to the adjacent “1” in the above pattern is obtainedas “2T”. In the present embodiment, in order to achieve high density ofan information storage medium, as described previously, a reproductionsignal from the repetition pattern (“10101010”) of “2T” recorded on theinformation storage medium is close to a shutdown frequency of MTF(Modulation Transfer Function) characteristics of an objective lens inan optical head (exists in the information recording/reproducing unit141 shown in FIG. 11); and thus, a degree of modulation (signalamplitude) is hardly obtained. Therefore, in the case where areproduction signal from a repetition pattern (“10101010”) of “2T” hasbeen used as a reproduction signal used for circuit tuning of theinformation reproducing apparatus or the informationrecording/reproducing apparatus (for example, initialing and optimizingtap coefficients in the tap controller 332 shown in FIG. 15), noiseeffect is significant, and stabilization is poor. Therefore, withrespect to a signal after modulated in accordance with RLL (1, 10) runlength restriction, then, it is desirable to carry out circuit tuning byusing a pattern of “3T” having high density.

In the case where a digital sum value (DSV) of the reproduction signalis considered, an absolute value of a DC (direct current) valueincreases in proportion to the number of continuous “0”s between “1” andnext “1” that immediately follows it, and the increased value is addedto the immediately preceding DSV value. The polarity of this added DCvalue is inverted every time “1” is reached. Therefore, as a method forsetting the DSV value to “0” where a channel bit pattern havingcontinuous reference code is followed, the DSV value is set to be “0” in12 channel bit patterns after ETM-modulated, whereby the degree offreedom in reference code pattern design is increased more significantlyby setting to an odd number the number of generated “1” appearing in 12channel bit patterns after ETM-modulated; offsetting a DC componentgenerated in one set of reference code cells consisting of a next set.Therefore, in the present embodiment, the number of “1” appearing in thereference code cells consisting of 12 channel bit patterns afterETM-modulated is set to an odd number.

In the present embodiment, in order to achieve high density, there isemployed a mark edge recording technique in which a location of “1”coincides with a boundary position of a recording mark or an emboss pit.For example, in the case where a repetition pattern of “3T”(“100100100100100100100”) is followed, there occurs a case in which alength of a recording mark or an emboss pit and a length of a spacebetween the mark and pit are slightly different from each otherdepending on a recording condition or an original master producingcondition. In the case where the PRML detecting technique has beenemployed, a level value of a reproduction signal becomes very important.As described previously, even in the case where the length of therecording mark or emboss pit and the length of the space between themark and pit are different from each other, there occurs a necessity ofcorrecting such slightly different component in a circuit manner so asto enable signal detection stably and precisely. Therefore, a referencecode for tuning a circuit constant has a space with a length of “3T”,like a recording mark or an emboss pit with a length of “3T”, therebyimproving the precision of tuning a circuit constant. Thus, if a patternof “1001001” is included as a reference code pattern according to thepresent embodiment, the recording mark or emboss pit having the length“3T”; and a space are always arranged.

In addition, circuit tuning also requires a pattern in a non-dense stateas well as a pattern (“1001001”) having a high density. Therefore, inconsideration of that fact that a non-dense state (pattern in which “0”is continuously and frequently generated) is generated at a portion atwhich a pattern of “1001001” has been excluded from among 12 channel bitpatterns after ETM-modulated and the number of generated “1”s is set inan odd number, with respect to a reference code pattern, a repetition of“100100100000” is obtained as an optical condition, as shown in FIGS.72A, 72B, 72C, and 72D. In order to ensure that the channel bit patternafter modulated is produced as the pattern, although not shown, there isa need for setting to “A4h” a data word before modulated, when utilizinga modulation table specified in an H format. This data on “A4h”(hexadecimal notation) corresponds to a data symbol “164” (decimalnotation).

A description will be given below with respect to how to producespecific data in accordance with the above data conversion rule. First,data symbol “164” (=“0A4h”) is set to main data “D0 to D2047” in thedata frame structure described previously. Next, a data frame 1 to adata frame 15 are pre-scrambled in advance by an initial preset number“0Eh”, and a data frame 16 to a data frame 31 are pre-scrambled inadvance by an initial preset number “0Fh”. If pre-scrambling is appliedin advance, when scrambling is applied in the data conversion ruledescribed previously, scrambling is applied in duplicate, and a datasymbol “164” (=“0A4h”) appears as it is (when scrambling is applied induplicate, an original pattern is returned). When pre-scrambling isapplied to all of the reference codes, each of which is formed of 32physical sectors, DSV control cannot be made, and thus, pre-scramblingcannot be applied to only data frame 0 in advance. After the foregoingscrambling has been applied, if modulation is carried out, a patternshown in FIGS. 72A, 72B, 72C, and 72D is recorded on the informationstorage medium.

Referring to FIGS. 66A to 66D, a description will be given with respectto a comparison in data recording format between a variety ofinformation storage mediums in the present embodiment. FIG. 66A shows adata recording format in a conventional read-only type informationstorage medium DVD-ROM; a conventional write-once type informationstorage medium DVD-R; and a conventional DVD-RW; FIG. 66B shows a datarecording format in a read-only type information storage medium in thepresent embodiment; FIG. 66C shows a data recording format of awrite-once type information storage medium in the present embodiment;and FIG. 66D shows a data recording format of a rewritable-typeinformation storage medium. For the sake of comparison, ECC blocks 411to 418 are shown as the same size. However, one ECC block is composed of16 physical sectors in the conventional read-only type informationstorage medium DVD-ROM shown in FIG. 66A; the conventional write-oncetype information storage medium DVD-R; and the conventional rewritabletype information storage medium DVD-RW, whereas, in the presentembodiment shown in FIGS. 66B to 66D, one ECC block is composed of 32physical sectors. The present embodiment is featured in that guard areas442 to 448 having the same length as a sync frame length 433 is providedbetween ECC blocks #1 411 to #8 418, as shown in FIGS. 66B to 66D.

In the conventional read-only type information storage medium DVD-ROM,ECC blocks #1 411 to #8 418 are continuously recorded as shown in FIG.66A. If an attempt is made to allocate compatibility in data recordingformat with the conventional read-only type information storage mediumDVD-ROM by means of the conventional write-once type information storagemedium DVD-R or the conventional rewritable type information storagemedium DVD-RW, if an additional writing or rewriting process calledrestricted overwrite is carried out, there has been a problem that partof the ECC block is damaged due to overwriting and the data reliabilityat the time of reproduction is significantly degraded. In contrast, asin the present embodiment, if guard areas 442 to 448 are arrangedbetween data fields (ECC blocks), there is attained advantageous effectthat an overwrite location is restricted to the guard areas 442 to 448,and the data damage in a data field (ECC block) can be prevented. Thepresent embodiment is secondarily featured in that the lengths of theabove guard areas 442 to 448 are adjusted to conform with a sync framelength 433 which is one sync frame size, as shown in FIGS. 66A to 66D.As shown in FIGS. 62A and 62B, sync codes are arranged in space indetermined sync frame lengths 433 having 1116 channel bits, and a synccode position is sampled by utilizing this predetermined cyclic space inthe sync code position detector unit 145 shown in FIG. 11. In thepresent embodiment, there is attained advantageous effect that, even ifthe guard areas 442 to 448 are encompassed at the time of reproductionby making adjustment to conform with the length sync frame length 433 ofthe guard areas 442 to 448, the sync frame space is kept unchanged, thusfacilitating sync code position detection at the time of reproduction.

Further, in the present embodiment, sync data is arranged in the guardarea for the purpose of:

1) improving detection precision of the sync code position detectionwhile matching a generation frequency of the sync codes even in alocation encompassing the guard areas 442 to 448; and

2) facilitating judgment of a position in a physical sector includingthe guard areas 442 to 448.

Specifically, as shown in FIG. 68, a postamble field 481 is formed atthe start position of each of the guard areas 442 to 468, and a synccode “SY1” of sync code number “1” shown in FIG. 63 is arranged in thatpostamble area 481. As is evident from FIGS. 62A and 62B, combinationsof sync code numbers of three continuous sync codes in a physical sectorare different from each other in all locations. Further, combinations ofsync code numbers of three continuous sync codes considering up to synccode numbers “1” in the guard areas 442 to 448 are also different fromeach other in all locations. Therefore, the judgment of a position inphysical sectors including a location of the guard area as well aspositional information in the physical sectors can be made in accordancewith sync code number combinations of three continuous sync codes in anarbitrary area.

FIG. 68 shows a detailed structure in the guard areas 441 to 448 shownin FIGS. 66A to 66D. The present embodiment is featured in that,although a structure in physical sectors is composed of a combination ofthe sync code 431 and sync data 432, the guard areas 441 to 448 iscomposed of a combination of a sync code 433 and sync data 434similarly; and, in an area of the sync data 434 contained in the guardarea #3 443, data is arranged, the data being modulated in accordancewith the same modulation rule as the sync data 432 in sectors. An areain one ECC block #2 412 composed of 32 physical sectors shown in FIG. 59is referred to as a data field 470 in the invention.

VFO (Variable Frequency Oscillator) areas 471 and 472 in FIG. 68 areutilized for synchronization of a reference clock of an informationreproducing apparatus or an information recording/reproducing apparatuswhen the data field 470 is reproduced. As the contents of data recordedin the areas 471 and 472, the data before modulated, in a commonmodulation rule described later, is obtained as a continuous repetitionof “7Eh”, and a channel bit pattern actually described after modulatedis obtained as a repetition of “010001 000100“Q (pattern in which three“0” settings are repeated). In order to obtain this pattern, it isnecessary to set the start bytes of the VFO areas 471 and 472 to State2.

The pre-sync areas 477 and 478 indicates a boundary position between theVFO areas 471 and 472 and the data area 470, and a recording channel bitpattern after modulated is a repetition of “100000 100000” (pattern inwhich continuous five “0” settings are repeated). The informationreproducing apparatus or the information recording reproducing apparatusdetects a pattern change position of a repetition pattern of “100000100000” in pre-sync areas 477 and 478 and recognizes that the data area470 approaches, from a repetition pattern of “010001 000100” containedin the VFO areas 471 and 472.

A postamble area 481 indicates an end position of the data area 470 anddesignates a start position of the guard area 443. A pattern in thepostamble area 481 coincides with a pattern of “SY1” in a SYNC codeshown in FIG. 63, as described above.

An extra area 482 is an area used for copy control or illegal copyprotection. In particular, in the case where this area is not used forcopy control or illegal copy protection, all “0s” are set by channelbits.

In a buffer area, data before modulated, which is identical to that inthe VFO areas 471 and 472, is obtained as a continuous repetition of““7Eh”, and the actually recorded channel bit pattern after modulated isobtained as a repetition pattern of “010001 000100” (pattern in whichcontinuous three 0 settings are repeated). In order to obtain thispattern, it is necessary to set the start bytes of the VFO areas 471 and472 to State 2.

As shown in FIG. 68, a postamble area 481 in which a pattern of “SY1” isrecorded corresponds to the sync code area 433; and an area from theimmediately succeeding extra area 482 to a pre-sync area 478 correspondsto the sync data area 434. An area from the VFO area 471 to the bufferarea 475 (namely, area including the data area 470 and part of thepreceding and succeeding guard areas) is referred to as a data segment490 in the invention. This area indicates the conditions different fromthose of a “physical segment” described later. The data size of eachitem of data shown in FIG. 68 is expressed by byte number of data beforemodulated.

In the present embodiment, without being limited to a structure shown inFIG. 68, the following method can be employed as another embodiment.That is, the pre-sync area 477 is arranged midway of the VOF areas 471and 472 shown in FIG. 68 instead of allocating the pre-sync area 477 atthe boundary section between the VOF area 471 and the data area 470. Insuch another embodiment, a distance correlation is taken by spacing adistance between a sync code “SY0” and the pre-sync area 477 arranged atthe start position of the data block 470; the pre-sync area 477 is setas pseudo-Sync; and the pre-sync area 477 is set as distance correlationinformation on a real Sync position (although it is different from adistance relevant to another Sync position). If a real Sync positioncannot be detected, Sync is inserted into a position at which the realposition generated from a pseudo Sync position would be detected.Another embodiment is featured in that the pre-sync area 477 is thusspaced slightly from real Sync (“SY0”). When the pre-sync area 477 isarranged at the beginning of the VFO areas 471 and 472, the role of thepre-sync becomes weaken because PLL of a read clock is not locked.Therefore, it is desirable that the pre-sync area 477 be arranged at theintermediate position of the VFO areas 471 and 472.

In the invention, address information in a recording type(rewritable-type or write-once) information storage medium is recordedin advance by using wobble modulation. The present embodiment isfeatured in that phase modulation of ±90 degrees (180 degrees) is usedas a wobble modulation system, and NRZ (Non Return to Zero) method isemployed, recording address information in advance with respect to aninformation storage medium. A specific description will be given withreference to FIG. 69. In the present embodiment, with respect to addressinformation, the 1-address bit (referred to as an address symbol) area511 is expressed by a four-wobble cycle, and a frequency and anamplitude/a phase are matched everywhere in the 1-address bit area 511.In the case where the same values of address bits are continued, thesame phase continuously lasts at the boundary section of the 1-addressbit areas 511 (at a portion indicated by “triangular mark” shown in FIG.69). In the case where an address bit is inverted, wobble patterninversion (180-degree shift of phase) occurs.

In the wobble signal detector unit 135 of the informationrecording/reproducing apparatus shown in FIG. 11, a boundary position ofthe above address bit area 511 (location indicated by “triangular mark”shown in FIG. 69) and a slot position 412 which is a boundary positionof a 1-wobble cycle are detected at the same time. Although not shown inthe wobble signal detector unit 135, a PLL (Phase Lock Loop) circuit isincorporated, and PLL is applied in synchronism with both of theboundary position of the above address bit area 511 and the slotposition 412. If the boundary position of this address bit area 511 orthe slot position 412 is shifted, the wobble signal detector unit 135 isout of synchronization, disabling precise wobble signal reproduction(reading). A gap between the adjacent slot positions 412 is referred toas a slot gap 513. As this slot gap 513 is physically closer,synchronization with a PLL circuit can be easily obtained, enablingstable wobble signal reproduction (reading of contained information).

As is evident from FIG. 69, this slot gap 513 coincides with a 1-wobblecycle if the phase modulation method of 180° is used in which the phaseis shifted by 0° or 180°. As a wobble modulating method, although an AM(Amplitude Modulation) system for changing a wobble amplitude is easilyaffected by dust or scratch adhering to the information storage mediumsurface, the above phase modulation is hardly comparatively affected bydust or scratch adhering to the information storage medium surfacebecause a change of a phase is detected instead of a signal amplitude inthe above phase modulation. As another modulation system, in an FSK(Frequency Shift Keying) system for changing a frequency, a slot gap 513is long with respect to a wobble cycle, and synchronization of a PLLcircuit is relatively hardly obtained. Therefore, as in the presentembodiment, when address information is recorded by wobble phasemodulation, there is attained advantageous effect that a slot gap isnarrow, and wobble signal synchronization is easily obtained.

As shown in FIG. 69, although binary data “1” or “0” is assigned to the1-address bit area 511, a method for allocating bits in the presentembodiment is shown in FIG. 70. As shown on the left side of FIG. 70, awobble pattern, which first wobbles from the start position of onewobble to the outer periphery side, is referred to as an NPW (NormalPhase Wobble), and data “0” is arranged. As shown at the right side, awobble pattern which first wobbles from the start position of one wobbleto the inner periphery side is referred to as an IPW (Invert PhaseWobble), and data “1” is arranged.

As shown in FIGS. 8B and 8C, the width Wg of the pre-groove region 11 islarger than the width W1 of the land region 12. Thus, a problem occursin which the detection signal level of the wobble detection signal islowered and the C/N ratio is lowered. Contrary to the prior art, anon-modulated area is wider than a modulated area so that the stabilityfor detecting a wobble signal is improved.

A description will be given with respect to a wobble address format inan H format of the embodiment with reference to FIGS. 106A to 106E. Asshown in FIG. 106B, a physical segment block includes seven physicalsegments 550-556. As shown in FIG. 106C, each of the physical segments550-556 includes seventeen wobble data units 560-576. Each of the wobbledata units 560-576 includes a modulation area which includes one of awobble sync area 580, modulation start marks 581, 582, wobble addressareas 586, 587 and non-modulation areas 590, 591 which includecontinuous NPWs. FIGS. 71A to 71D show a ratio of the non-modulationarea and the modulation area of each wobble data unit. In each of FIGS.71A to 71D, the modulation area 598 includes 16 wobbles and thenon-modulation area 593 includes 68 wobbles. According to theembodiment, the non-modulation area 593 is wider than the modulationarea 598. Since the non-modulation area 593 is wide, it is possible tostably synchronize the wobble detection signal, write clock, orreproduction clock by the PLL circuit using the signal from thenon-modulation area 593. In order to perform a stable synchronization,it is desirable set the width of the non-modulation area 593 at leastdouble of that of the modulation area 598.

A description will be given with respect to an address informationrecording format using wobble modulation in an H format of a write-oncetype information storage medium according to the invention. An addressinformation setting method using wobble modulation in the presentembodiment is featured in that “allocation is carried out in units ofthe sync frame length 433” shown in FIGS. 66A to 66D. As shown in FIGS.62A and 62B, one sector is composed of 26 sync frames, and, as isevident from FIG. 56, one ECC block is formed of 32 physical sectors.Thus, one ECC block is composed of 32 physical sectors and is composedof 832 (=26×327) sync frames.

As shown in FIGS. 66A to 66D, a length of the guard areas 442 to 468which exist between the ECC blocks 411 to 418 coincides with one syncframe length 433, and thus, a length obtained by adding one guard area462 and one ECC block 411 to each other is composed of 832+1=833 syncframes. Prime factorization can be carried out into 833=7×17×7, andthus, a structural allocation utilizing this feature is provided. Thatis, a basic unit of data capable of writing an area equal to a length ofan area obtained by adding one guard area and one ECC block to eachother is defined as a data segment 531 (A structure in the data segment490 shown in FIG. 68 coincides with one another regardless of theread-only type information storage medium, the rewritable-typeinformation storage medium, or the write-once type information storagemedium); an area having the same length as a physical length of one datasegment 490 is divided into “seven” physical segments, and addressinformation is recorded in advance in the form of wobble modulation on aphysical segment by segment basis.

A boundary position relevant to the data segment 490 and a boundaryposition relevant to a physical segment do not coincide with each other,and are shifted by an amount described later. Further, wobble data isdivided into 17 WDU (Wobble Data Units), respectively, on a physicalsegment by segment basis. From the above formula, it is evident thatseven sync frames are arranged to a length of one wobble data unit,respectively. Thus, a physical segment is composed of 17 wobble dataunits, and seven physical segment lengths are adjusted to conform with adata segment length, thereby making it easy to allocate a sync frameboundary and detect a sync code in a range encompassing guard areas 442to 468.

Each of the wobble data units #0 560 to #11 571 is composed of: amodulation area 598 for 16 wobbles; and non-modulation areas 592 and 593for 68 wobbles, as shown in FIGS. 71A to 71D. The present embodiment isfeatured in that an occupying ratio of the non-modulation areas 592 and593 with respect to a modulation area is significantly large. In thenon-modulation areas 592 and 593, a group area or a land area alwayswobbles at a predetermined frequency, and thus, a PLL (Phase LockedLoop) is applied by utilizing the non-modulation areas 592 and 593,making it possible to stably sample (generate) a reference clock whenreproducing a recording mark recorded in the information storage mediumor a recording reference clock used at the time of new recording. Thus,in the present embodiment, an occupying ratio of the non-modulationareas 592 and 593 with respect to a modulation area 598 is significantlyincreased, thereby making it possible to remarkably improve theprecision of sampling (generating) a recording reference clock andremarkably improving the stability of the sampling (generation). Thatis, in the case where phase modulation in wobbles has been carried out,if a reproduction signal is passed through a band path filter for thepurpose of waveform shaping, there appears a phenomenon that a detectionsignal waveform amplitude after shaped is reduced before and after aphase change position. Therefore, there is a problem that, when thefrequency of a phase change point due to phase modulation increases, awaveform amplitude change increases, and the above clock samplingprecision drops; and, conversely, if the frequency of a phase changepoint in a modulation area is low, a bit shift at the time of wobbleaddress information detection is likely to occur. Thus, in the presentembodiment, there is attained advantageous effect that a modulation areaand a non-modulation area due to phase modulation configured, and anoccupying ratio of the non-modulation area is increased, therebyimproving the above clock sampling precision.

In the present embodiment, a position of switching the modulation areaand the non-modulation area can be predicted in advance. Thus, areproduction signal is gated to obtain a signal from the non-modulationarea, making it possible to carry out the above clock sampling from thatdetection signal. In addition, in the case where the recording layer 3-2is composed of an organic dye recording material using a principle ofrecording according to the present embodiment, a wobble signal iscomparatively hardly taken in the case of using the pre-grooveshape/dimensions described in “3-2-D] Basic characteristics relevant topre-groove shape/dimensions in the present embodiment” in “3-2)Description of basic characteristics common to organic dye film in thepresent embodiment”. In consideration of this situation, the reliabilityof wobble signal detection is improved by significantly increasing anoccupying ratio of the non-modulation areas 590 and 591 with respect toa modulation area, as described above.

At the boundary between the non-modulation areas 592 and 593 and themodulation area 598, an IPW area is set as a modulation start mark ofthe modulation area 598 by using four wobbles or six wobbles. At awobble data section shown in FIGS. 71C and 71D, allocation is carriedout so that wobble address areas (address bits #2 to #0)wobble-modulated immediately after detecting the IPW area which is thismodulation start mark. FIGS. 71A and 71B each show the contents in awobble data unit #0 560 which corresponds to a wobble sync area 580shown in FIG. 72C described later; and FIGS. 71C and 71D each show thecontents in a wobble data unit which corresponds to a wobble datasection from segment information 727 to a CRC code 726 shown in FIG.72C. FIGS. 71A and 71C each show a wobble data unit which corresponds toa primary position 701 in a modulation area described later; and FIGS.71B and 71D each show a wobble data unit which corresponds to asecondary position 702 in a modulation area. As shown in FIGS. 71A and71B, in a wobble sync area 580, six wobbles are allocated to the IPWarea, and four wobbles are allocated to an NPW area surrounded by theIPW area. As shown in FIGS. 71C and 71D, four wobbles are allocated to arespective one of the IPW area and all of the address bit areas #2 to #0in the wobble data section.

FIGS. 72A to 72D shows an embodiment relating to a data structure inwobble address information in a write-once type information storagemedium. For the sake of comparison, FIG. 72A shows a data structure inwobble address information of a rewritable-type information storagemedium. FIGS. 72A and 72C show two embodiments relating to a datastructure in wobble address information in the write-once typeinformation storage medium.

In a wobble address area 610, three address bits are set by 12 wobbles(referring to FIG. 69). Namely, one address bit is composed of fourcontinuous wobbles. Thus, the present embodiment employs a structure inwhich address information is arranged to be distributed on three bythree address bit basis. When the wobble address information 610 isintensively recorded at one site in an information storage medium, itbecomes difficult to detect all information when dust or scratch adheresto the medium surface. As in the present embodiment, there is attainedadvantageous effect that: wobble address information 610 is arranged tobe distributed on a three by three address bit (12 wobbles) basisincluded in one of the wobble data units 560 to 576; and a set ofinformation is recorded on an integer multiple by multiple address bitbasis of three address bits, enabling information detection of anotheritem of information even in the case where it is difficult to detectinformation in one site due to dust or scratch.

As described above, the wobble address information 610 is arranged to bedistributed, and the wobble address information 610 is completelyarranged on a one by one physical segment basis, thereby making itpossible to identify address information on a physical segment bysegment basis, and thus, identify a current position in physical segmentunits every time an information recording/reproducing apparatus providesan access.

In the present embodiment, an NRZ technique is employed as shown in FIG.69, and thus, a phase does not change in four continuous wobbles in thewobble address area 610. A wobble sync area 580 is set by utilizing thischaracteristic. That is, a wobble pattern which is hardly generated inthe wobble address information 610 is set with respect to the wobblesync area 580, thereby facilitating allocation position identificationof the wobble sync area 580. The present embodiment is featured in that,with respect to wobble address areas 586 and 587 in which one addressbit is composed of four continuous wobbles, one address bit length isset at a length other than four wobbles at a position of the wobble syncarea 580. That is, in the wobble sync area 580, as shown in FIGS. 71Aand 71B, an area (IPW area) in which a wobble bit is set to “1” is setas a wobble pattern change which does not occur in the wobble datasection as shown in FIGS. 71C and 71D such as “six wobbles→fourwobbles→six wobbles”. When a method for changing a wobble cycle asdescribed above is utilized as a specific method for setting a wobblepattern which can be hardly generated in the wobble data section withrespect to the wobble sync area 580, the following advantageous effectscan be attained:

1) Wobble detection (wobble signal judgment) can be stably continuedwithout distorting PLL relating to the slot position 512 (FIG. 69) of awobble which is carried out in the wobble signal detector unit 135 shownin FIG. 11; and

2) A wobble sync area 580 and modulation start marks 561 and 562 can beeasily detected due to a shift of an address bit boundary positiongenerated in the wobble signal detector unit 135 shown in FIG. 11.

As shown in FIGS. 71A to 71D, the present embodiment is featured in thatthe wobble sync area 580 is formed in 12 wobble cycles, and a length ofthe wobble sync area 580 is made coincident with three address bitlengths. In this manner, all the modulation areas (for 16 wobbles) inone wobble data unit #0 560 are arranged to the wobble sync area 580,thereby improving detection easiness of the start position of wobbleaddress information 610 (allocation position of wobble sync area 580).This wobble sync area 580 is arranged in the first wobble data unit in aphysical segment. Thus, there is attained advantageous effect that thewobble sync area 580 is arranged to the start position in a physicalsegment, whereby a boundary position of the physical segment can beeasily sampled merely by detecting a position of the wobble sync area580.

As shown in FIGS. 71C and 71D, in wobble data units #1 561 to #11 571,the IPW area (refer to FIG. 70) is arranged as a modulation start markat the start position, the area preceding address bits #2 to #0. Thewaveform of NPW is continuously formed in the non-modulation areas 592and 593 arranged at the preceding position. Thus, the wobble signaldetector unit 135 shown in FIG. 11 detects a turning point from NPW toIPW is detected, and samples the position of the modulation start mark.

As a reference, the contents of wobble address information 610 containedin a rewritable-type information storage medium shown in FIG. 72A are asfollows:

1) Physical Segment Address 601

Information indicating a physical segment number in a track (within onecycle in an information storage medium 221);

2) Zone Address 602

This address indicates a zone number in the information storage medium221; and

3) Parity Information 605

This information is set for error detection at the time of reproductionfrom the wobble address information 610; 14 address bits from reservedinformation 604 to the zone address 602 are individually added in unitsof address bits; and a display as to whether or not a result of theaddition is an even number or an odd number is made. A value of theparity information 605 is set so that a result obtained by takingexclusive OR in units of address bits becomes “1” with respect to atotal of 15 address bits including one address bit of this addressparity information 605.

4) Unity Area 608

As described previously, each wobble data unit is set so as to becomposed of a modulation area 598 for 16 wobbles and non-modulationareas 592 and 593 for 68 wobbles, and an occupying ratio of thenon-modulation areas 592 and 593 with respect to the modulation area 598is significantly increased. Further, the precision and stability ofsampling (generation) of a reproducing reference clock or a recordingreference clock is improved more remarkably by increasing the occupyingratio of the non-modulation areas 592 and 593. The NPW area is fullycontinuous in a unity area 608, and is obtained as a non-modulation areahaving its uniform phase.

FIG. 72A shows the number of address bits arranged to each item of theabove described information. As described above, the wobble addressinformation 610 is divided on a three by three address bits, and thedivided items of the information are arranged to be distributed in eachwobble data unit. Even if a burst error occurs due to the dust orscratch adhering to a surface of an information storage medium, there isa very low probability that such an error propagates across the wobbledata units which are different from each other. Therefore, a contrivanceis made so as to reduce to the minimum the count encompassing thedifferent wobble data units as locations in which the same informationis recorded and to match the turning point of each items of informationwith a boundary position of a wobble data unit. In this manner, even ifa burst error occurs due to the dust or scratch adhering to a surface ofan information storage medium, and then, specific information cannot beread, the reliability of reproducing of wobble address information isimproved by enabling reading of another item of information recorded inanother one of the wobble data units.

As shown in FIGS. 72A to 72D, the present embodiment is featured in thatthe unity areas 608 and 609 are arranged at the end in the wobbleaddress information 610. As described above, in the unity areas 608 and609, a wobble waveform is formed in the shape of NPW, and thus, the NPWcontinuously lasts in substantially three continuous wobble data units.There is attained advantageous effect that the wobble signal detectorunit 135 shown in FIG. 11 makes a search for a location in which NPWcontinuously lasts in a length for three wobble data units 576 byutilizing this feature, thereby making it possible to easily sample aposition of the unity area 608 arranged at the end of the wobble addressinformation 610, and to detect the start position of the wobble addressinformation 610 by utilizing the positional information.

From among a variety of address information shown in FIG. 72A, aphysical segment address 601 and a zone address 602 indicate the samevalues between the adjacent tracks, whereas a value changes between theadjacent tracks in a groove track address 606 and a land track address607. Therefore, an indefinite bit area 504 appears in an area in whichthe groove track address 606 and the land track address 607 arerecorded. In order to reduce a frequency of this indefinite bit, in thepresent embodiment, an address (number) is displayed by using a graycode with respect to the groove track address 606 and the land trackaddress 607. The gray code denotes a code in the case where a code afterconverted when an original value changes by “1” only changes by “onebit” anywhere. In this manner, the indefinite bit frequency is reduced,making it possible to detect and stabilize a reproduction signal from arecording mark as well as a wobble detecting signal.

As shown in FIGS. 72B and 72C, in a write-once type information storagemedium as well, as in the rewritable-type information storage medium, awobble sync area 580 is arranged at the start position of a physicalsegment, thereby making it easy to detect the start position of thephysical segment or a boundary position between the adjacent segments.Type identification information 721 on the physical segment shown inFIG. 72B indicates an allocation position in the physical segment as inthe wobble sync pattern contained in the above described wobble syncarea 580, thereby making it possible to predict in advance an allocationlocation of another modulation area 598 in the same physical segment andto prepare for next modulation area detection. Thus, there is attainedadvantageous effect that the precision of signal detection (judgment) ina modulation area can be improved. Specifically,

When type identification information 721 on a physical segment is set to“0”, it denotes that all the items of information in the physicalsegment shown in FIG. 74B are arranged at a primary position or that aprimary position and a secondary position shown in FIG. 74D are mixed;and

When type identification information 721 of a physical segment is set to“1”, all items of information in a physical segment are arranged at asecondary position, as shown in FIG. 74C.

According to another embodiment relevant to the above describedembodiment, it is possible to indicate an allocation location of amodulation area in a physical segment by using a combination between awobble sync pattern and type identification information 721 on aphysical segment. By using the combination of the two types ofinformation described previously, three or more types of allocationpatterns of modulation areas shown in FIGS. 74B to 74D can be expressed,making it possible to provide a plurality of allocation patterns of themodulation areas. While the above described embodiment shows anallocation location of a modulation area in a physical segment whichincludes a wobble sync area 580 and type identification information 721on a physical segment, the invention is not limited thereto. Forexample, as another embodiment, the wobble sync area 580 and the typeidentification information 721 on the physical segment may indicate anallocation location of a modulation area in a next physical segment. Bydoing this, in the case where tracking is carried out continuously alonga groove area, there is attained advantageous effect that the allocationlocation of the modulation area in the next physical segment can beidentified in advance, and a long preparation time for detecting amodulation area can be taken.

Layer number information 722 in a write-once type information storagemedium shown in FIG. 72B indicates either of the recording layers fromamong a single-sided single-layer or a single-sided double-layer. Thisinformation denotes:

“L0 later” in the case of a single-sided single-layer medium or asingle-sided double-layer medium when “0” is set (a front layer at thelaser light beam incident side); and

“L1 layer” of a single-sided double-layer when “1” is set (a rear layerin viewed from the laser light beam incident side).

Physical segment sequence information 724 indicates an allocationsequence of relative physical segments in the same physical segmentblock. As is evident as compared with FIG. 72A, the start position ofthe physical segment sequence information 724 contained in wobbleaddress information 610 coincides with that of a physical segmentaddress 601 contained in a rewritable-type information storage medium.The physical segment sequence information position is adjusted toconform with the rewritable-type medium, thereby making it possible toimprove compatibility between medium types and to share or simplify anaddress detection control program using a wobble signal in aninformation recording/reproducing apparatus in which both of arewritable-type information storage medium and a write-once typeinformation storage medium can be used.

A data segment address 725 shown in FIG. 72B describes addressinformation on a data segment in numbers. As has already been described,in the present embodiment, one ECC block is composed of 32 sectors.Therefore, the least significant five bits of a physical sector numberof a sector arranged at the beginning in a specific ECC block coincideswith that of a sector arranged at the start position in the adjacent ECCblock. In the case where a physical sector number has beet set so thatthe least significant five bits of the physical sector number of asector arranged in an ECC block are “00000”, the values of the leastsignificant six bits or more of the physical sector numbers of all thesectors which exist in the same ECC block coincide with each other.Therefore, the least significant five bit data of the physical sectornumber of the sectors which exist in the same ECC block is eliminated,and address information obtained by sampling only the least significantsix bits or more is defined as an ECC block address (or ECC blockaddress number). A data segment address 725 (or physical segment blocknumber information) recorded in advance by wobble modulation coincideswith the above ECC block address. Thus, when positional information on aphysical segment block due to wobble modulation is indicated by a datasegment address, there is advantageous effect that a data amountdecreases on five by five bit basis as compared with when the address isdisplayed by a physical sector number, simplifying current positiondetection at the time of an access.

A CRC code 726 shown in FIGS. 72B and 72C is a CRC code (errorcorrection code) arranged to 24 address bits from physical segment typeidentification information 721 to the data segment address 725 or a CRCcode arranged to 24 address bits from segment information 727 to thephysical segment sequence information 724. Even if a wobble modulationsignal is partially mistakenly read, this signal can be partiallycorrected by this CRC code 726.

In a write-once type information storage medium, an area correspondingto 15 address bits is arranged to the unity area 609, and an NPW area isfully arranged in five wobble data units 12 to 16 (the modulation area598 does not exist).

A physical segment block address 728 shown in FIG. 72C is an address setfor each physical segment block which configure one unit from sevenphysical segments, and a physical segment block address relevant to thefirst segment block in the data lead-in area DTRDI is set to “1358h”.The values of the physical segment block addresses are sequentiallyadded one by one from the first physical segment block contained in thedata lead-in area DTLDI to the last physical segment block contained inthe data lead-out area DTLD0, including the data area DTA.

The physical segment sequence information 724 denotes the sequence ofeach of the physical segments in one physical segment block, and “0” isset to the first physical segment, and “6” is set to the last physicalsegment.

The embodiment shown in FIG. 72C is featured in that the physicalsegment block address 728 is arranged at a position which precedes thephysical segment sequence information 724. For example, as in the RMDfield 728 shown in FIG. 53, address information is often managed by thisphysical segment block address. In the case where an access is providedto a predetermined segment block address in accordance with these itemsof management information, first, the wobble signal detector unit 135shown in FIG. 11 detects a location of the wobble sync area 580 shown inFIG. 72C, and then, sequentially decodes items of information recordedimmediately after the wobble sync area 580. In the case where a physicalsegment block address exists at a position which precedes the physicalsegment sequence information 724, first, the physical segment blockaddress is decoded, and it is possible to judge whether or not apredetermined physical segment block address exists without decoding thephysical segment sequence information 724. Thus, there is advantageouseffect that access capability using a wobble address is improved.

The segment information 727 is composed of type identificationinformation 721 and a reserved area 723. The type identificationinformation 721 denotes an allocation location of a modulation area in aphysical segment. In the case where the value of this typeidentification information 721 is set to “0b”, it denotes a state shownin FIG. 74B described layer. In the case where the information is set to“1b”, it denotes a state shown in FIG. 74C or FIG. 74D described later.

The present embodiment is featured in that type informationidentification 721 is arranged immediately after the wobble sync area580 in FIG. 72C. As described above, first, the wobble signal detectorunit 135 shown in FIG. 11 detects a location of the wobble sync area 580shown in FIG. 72C, and then, sequentially decodes the items ofinformation recorded immediately after the wobble sync area 580.Therefore, the type identification information 721 is arrangedimmediately after the wobble sync area 580, thereby enabling anallocation location check of a modulation area in a physical segmentimmediately. Thus, high speed access processing using a wobble addresscan be achieved.

Referring to FIG. 79, a description will be given with respect to anoccurrence of a crosstalk of a wobble signal from the adjacent track.

As shown in FIG. 79, a pre-groove area 1011 is provided on a recordableinformation storage medium with wobbling. At the time of informationreproduction and at the time of turning ON a track loop, a focusing spot1027 is tracking the pre-groove area 1011 while the focusing spot 1027is tracing the pre-groove area 1011. A wobble frequency of thepre-groove area 1011 is higher than a tracking servo bandwidth, andtherefore, tracking correction is not carried out, thereby detecting awobble signal (a signal detected due to a difference (I1−I2) between adetection signal I1 detected from an optical detection cell 1025 a and adetection signal I2 detected from an optical detection cell 1025 b in anoptical detector 1025 shown in FIG. 82A). As shown in FIG. 79, in thecase where the phase of wobbles are inverted between the adjacenttracks, when the focusing spot 1027 is set at a position as shown in (a)of FIG. 79, a crosstalk of a wobble signal from the adjacent track doesnot occur. However, when the focusing spot 1027 is set at a positionshown in (b) of FIG. 79, part of the pre-groove area 1015 of theadjacent track enters the focusing spot 1027. Therefore, a wobble signalof the adjacent track appears as a crosstalk.

The present embodiment is featured in that a reproduction signal qualityis defined so that a crosstalk quantity of a wobble signal is restrictedto be equal to or smaller than a specific value.

Referring to a flow chart shown in FIG. 81, a description will be givenwith respect to a method for measuring a maximum amplitude (Wppmax) anda minimum amplitude (Wppmin) of a wobble detection signal. At #01, awobble signal is input to a spectrum analyzer.

Here, parameters of the spectrum analyzer are set as follows:

Center frequency: 697 kHz

Frequency span: 0 Hz

Resolution bandwidth: 10 kHz

Video bandwidth: 30 Hz

Next, a linear speed is adjusted while a rotation frequency of a disc ischanged so that a wobble signal frequency is obtained as a predeterminedvalue at #02.

In the present embodiment, an H format is used, and thus, thepredetermined value of the wobble signal is set to 697 kHz.

Now, a description will be given with respect to an example ofmeasurement of a maximum value (Cwmax) and a minimum value (Cwmin) of acarrier level of a wobble detection signal.

As shown in FIG. 80, in the write-once type storage medium according tothe present embodiment, a CLV (Constant Linear Velocity) recordingsystem is used, and thus, a wobble phase between the adjacent trackschanges depending on a track position. In the case where the wobblephases between the adjacent tracks coincide with each other, the carrierlevel of the wobble detection signal is maximized, and is obtained asthe maximum value (Cwmax). In addition, when the wobble phase betweenthe adjacent tracks is inverted, the wobble detection signal level isminimized due to the crosstalk of the adjacent tracks, and is obtainedas the minimum value (Cwmin). Therefore, in the case where tracing iscarried out along a track from its inner periphery to its outerperiphery, the size of a carrier of a wobble detection signal to bedetected fluctuates in a 4-track cycle, as shown in FIG. 80.

In the present embodiment, a wobble carrier signal is detected on a 4×4track basis, and the maximum value (Cwmax) and the minimum value (Cwmin)are measured on a 4 x 4 track basis. Then, at #03, 30 pairs or more ofthe maximum value (Cwmax) and the minimum value (Cwmin) are stored.

Next, utilizing the formula below, at #04, the maximum amplitude(Wppmax) and the minimum amplitude (Wppmin) are calculated from anaverage value of the maximum value (Cwmax) and the minimum value(Cwmin).

In the formula below, R represents a terminated resistance value of thespectrum analyzer. Now, a description will be given with respect to aformula for converting Wppmax and Wppmin from the values of Cwmax andCwmin.

In a dBm unit system, 0 dBm=1 mW is defined as a reference. When powerWa=1 mW, a voltage amplitude Vo is obtained as follows:Wao=Ivo=Vo×Vo/R=1/1000 W.

Therefore, Vo=(R/1000)^(1/2) is obtained.

Next, a relationship between a wobble amplitude Wpp [V] and a carrierlevel Cw [dMb] monitored by the spectrum analyzer is as follows. Here,Wpp denotes a sine wave, and thus, when an amplitude is converted to anactually effective value, it follows:Wpp−rms=Wpp/(2×2^(1/2))Cw=20×log (Wpp−rms/Wo) [dBm]

Therefore, Cw=10×log (Wpp−rms/Vo)² is established.

When the log of the above formula is converted, it follows:$\begin{matrix}{\begin{matrix}{\left( {{Wpp} - {{rms}/{Vo}}} \right)^{2} = {10\left( {{Cw}/10} \right)}} \\{= \left\{ {\left\lbrack {{Wpp}/\left( {2 \times 2^{1/2}} \right)} \right\rbrack/{Vo}} \right\}^{2}} \\{= \left\{ {{{Wpp}/\left( {2 \times 2^{2}} \right)}//\left( {R/1000} \right)^{1/2}} \right\}^{2}} \\{= \left( {{{Wpp}^{2}/8}/\left( {R/1000} \right)} \right.}\end{matrix}\begin{matrix}{{{WPP}\quad 2^{2}} = {\left( {8 \times R} \right)/\left( {1000 \times 10^{({{Cw}/10})}} \right)}} \\{= {8 \times R \times 10^{({- 3})} \times 10^{({{Cw}/10})}}} \\{= {8 \times R \times 10^{{({{Cw}/10})}{({- 3})}}}}\end{matrix}{Wpp} = \left\{ {8 \times R \times 10\left( {{Cw}/10^{({- 3})}} \right\}^{1/2}} \right.} & (61)\end{matrix}$

Now, characteristics of a wobble signal and a track shift detectionsignal are shown in FIGS. 82A and 82B.

An optical head shown in FIG. 82A exists in an informationrecording/reproducing section 141 shown in FIG. 11. Then, (I1−I2) signalthat is a track shift detection signal detected by the optical headshown in FIG. 82A is output from the information recording/reproducingsection 141 shown in FIG. 11, and then, the resultant signal is input toa wobble signal detecting section 135 shown in FIG. 11.

A description will be given with respect to an internal structure of anoptical head that exists in the information recording/reproducingsection 141 shown in FIG. 11. As shown in FIG. 82A, laser light beamsemitted from a semiconductor laser 1021 are produced as parallel lightbeams by means of a collimator lens 1022; the produced light beams arefocused by means of an objective lens 1028 via a beam splitter 1023; andthe focused light beams are irradiated into a pre-groove area 1011 of aninformation recording medium 1001. The pre-groove area 1011 carries outfine wobbling. The light beams reflected from the wobbled pre-groovearea 1011 passes through the objective lens 1028 again; the resultinglight beams are reflected by means of the beam splitter 1023; and thereflected beams are irradiated toward an optical detector 1025 by meansof a focusing lens 1024.

The optical detector 1025 is composed of an optical detection cell1025-1 and an optical detection cell 1025-2; a difference betweensignals I1 and I2 detected from the respective optical detection cells1025-1 and 1025-2 is obtained; and the resulting signal is input to thewobble signal detecting section 135 shown in FIG. 11. The optical headshown in FIG. 82A can detect a wobble signal and a track shift detectionsignal that conforms to a push-pull system.

When a track loop is turned ON, the bandwidth of a wobble frequency ishigher than a tracking bandwidth, and thus, a wobble signal is detectedby the optical head. Here, when the wobble phases of the pre-groovesbetween the adjacent tracks are equal to each other, the maximumamplitude of Wppmax is obtained. When the phases are inverted, thewobble signal amplitude is lowered due to an effect of the crosstalk ofthe adjacent tracks, and is obtained as the minimum amplitude Wppmin.

In the present embodiment, a condition between the maximum amplitude(Wppmax) and the minimum amplitude (Wppmin) is defined, and contrivanceis made so as to enable more stable wobble detection. That is, thewobble signal detecting section 135 shown in FIG. 11 is designed so asto stably enable signal detection even if the amplitude value of awobble detection signal changes up to a maximum of 3 times as large asusual. In addition, it is desirable that a change rate of the amplitudeof a wobble detection signal be equal to or smaller than ½ as low asusual in consideration of an effect caused by a crosstalk.

Therefore, in the present embodiment, an intermediate value of the abovevalues is taken, and a value obtained by dividing a maximum value of anallowable wobble signal by a minimum value of a wobble signal(Wppmax/Wppmin) is set to 2.3 or less.

While the present embodiment sets the value of (Wppmax/Wppmin) to 2.3 orless, a signal can be stably detected even if the value of(Wppmax/Wppmin) is 3 or less in view of the performance of the wobblesignal detecting section 135 shown in FIG. 11. In addition, in the caseof carrying out wobble detection with higher precision, the value of(Wppmax/Wppmin) can be set to 2.0 or less. The wobble amplitude of thepre-groove area 1011 is set so as to meet the above-described condition.

As shown in FIG. 82B, in the case where a track loop has been turnedOFF, a track shift detection signal is output from an optical head. Atthis time, the maximum amplitude of a track shift detection signal isrepresented by (I1−I2)pp. This value of (I1−I2)pp is obtained by findinga difference between an I1 signal detected by an optical detection cell1025-1 and an I2 signal detected by an optical detection cell 1025-2.The thus obtained signal is processed after passing through a low-passfilter for a shutdown frequency (cutoff frequency) of 30 kHz. Thislow-pass filter is composed of a primary filter. In addition, this valueof (I1−I2)pp is measured in an unrecorded data area (DTA) and a datalead-in area (DTLDI) or a data lead-out area (DTLD0) in an unrecordedarea.

Now, a method for measuring an amplitude value (I1−I2) of a track shiftdetection signal will be described with reference to FIG. 83.

At #11, (I1−I2) signal obtained from the optical head shown in FIG. 82Ais input to a low-pass filter for a shutdown frequency (cutofffrequency) fc=30 kHz.

At #12, an amplitude value is measured with respect to a low-pass filteroutput on a track by track basis, and 30 or more samples areaccumulated.

By taking an average of the samples obtained at #12, (I1−I2) is found at#13.

The present embodiment is featured in that the minimum value (Wppmin) ofan amplitude of a wobble signal is defined with respect to an amplitude(I1−I2)pp of a track shift detection signal when a track loop is turnedOFF. An information storage/reproducing apparatus according to thepresent embodiment shown in FIG. 11 is primarily featured in that awobble signal is detected by means of a wobble signal detecting section135 and in that a track shift detection signal is detected using thesame detecting circuit. A wobble signal and a track shift detectionsignal are detected by means of the wobble signal detecting section 135,whereby one detecting circuit can process (carries out) two jobs, thusmaking it possible to promote circuit simplification.

The wobble signal detecting section 135 is featured in that a dynamicrange of this circuit is sometimes adjusted to an amplitude value(I1−I2) of a track shift detection signal. In this case, since a wobblesignal is detected by means of the same circuit, if the minimum value(Wppmin) of an amplitude value of a wobble detection signal issignificantly smaller than the amplitude of a track shift detectionsignal, the detection precision of the wobble detection signal islowered, and a stable processing operation cannot be made.

Therefore, in the wobble signal detecting section 135 shown in FIG. 11,in order to stably detect a signal, it is desirable that the minimumvalue (Wppmin) of the amplitude value of the wobble signal be greaterthan 0.2 with respect to the amplitude value (I1−I2)pp of the trackshift detection signal. However, as signal characteristics of the wobblesignal detecting section, a wobble signal can be stably detected up to5% of the amplitude value (I1−I2)pp of the track shift detection signal.The wobble amplitude of the pre-groove area 11 is set so as to meet theabove-described condition.

Therefore, in the present embodiment, while the above-describedintermediate value is taken, and the minimum value (Wppmin) of theamplitude value of the wobble detection signal is set to 0.1 or morewith respect to the amplitude value (I1−I2)pp of the track shiftdetection signal. As a result, it is possible to guarantee that thedetection precision of the wobble detection signal is improved withrespect to (I1−I2)pp. The present embodiment is featured in that theamplitude of the wobble detection signal is set as described above and aC/N ratio of the wobble signal is defined, thereby improving thedetection precision of the wobble signal.

FIG. 84 shows a circuit for measuring a C/N ratio with respect to awobble signal.

The C/N ratio of a wobble detection signal in the present embodiment isdetected using an (I1−I2) signal output from an optical head shown inFIG. 82A. The wobble detection signal from a pre-groove area 1011 isdetected by means of the (I1−I2) signal (FIGS. 82A and 82B) obtainedwhen tracing has been carried out on the data lead-in area (DTLDI), thedata area (DTA), or the data lead-out area (DTLD0) shown in FIGS. 39A to39D. The evaluation of the wobble detection signal is executed by anNBSNR (Narrow-Band Signal-To-Noise Ratio) shown below, of the wobbledetection signal. In the present embodiment, a value of NBSNR of aresult obtained by squaring the wobble detection signal is set to beequal to or greater than 20 dB, and is preferably set to be equal to orgreater than 26 dB. An information storage medium is manufactured sothat a noise component of the pre-groove area 1011 is reduced so as tomeet the above-described condition.

The value of NBSNR of the result obtained by squaring this wobbledetection signal needs to be equal to or greater than 26 dB on anunrecorded track and needs to meet the condition of 26 dB or more evenon a recorded track.

Now, a description will be given below with respect to a circuit andmethod for measuring NBSNR.

An (I1−I2) signal output from the optical head shown in FIG. 82A isinput to a preamplifier circuit 1031 as a wobble signal 1030, and then,the input signal is input to a primary band-pass filter 1032. Next, thesignal having passed through the band-pass filter 1032 is converted intoa squared waveform by means of a squaring circuit 1033, and then, theconverted signal is input to a spectrum analyzer 1034. At this time, theparameters of the spectrum analyzer 1034 are set as follows:

Center frequency: 1.39 MHz

Frequency span: 500 kHz

Resolution bandwidth: 10 kHz

Video bandwidth: 10 kHz or more

Sweep time: 50 ms

128 or more averaging operations

Now, referring to a flow chart shown in FIG. 85, a description will begiven with respect to a specific method for measuring NBSNR. First,continuous random data for 400 or more tracks is recorded on aninformation storage medium at #21. Next, at #22, a carrier level and anoise level are measured while in tracking without track jump on a trackrecorded at #21. Based on a difference between the carrier level and thenoise level measured at 22, NBSNR is obtained at #23.

FIG. 88 shows a spectrum analyzer waveform of a wobble detection signalafter squared. The carrier level is indicated by a maximum peak valueincluded in the spectra. In addition, the noise level is defined by anaverage value of 1.14 MHz to 1.19 MHz and an average value of 1.59 MHzto 1.64 MHz.

Now, a description will be given with respect to a reason why a squaringcircuit (1033 shown in FIG. 84) has been used to measure a C/N ratio ofa wobble detection signal in the present embodiment. As shown in FIGS.86A and 86B, in an embodiment of an H format, a wobble detection signalis assigned by means of phase modulation. In the case of phasemodulation, as shown in FIG. 86A, a number of frequency components areprovided at a transition portion α of a phase transition portion(between NPW and IPW). Thus, when the waveform of the wobble detectionsignal shown in FIG. 86A is analyzed by means of the spectrum analyzer1034, great peaks appear at the periphery of a carrier, as shown in FIG.87. Therefore, it becomes difficult to define a noise level.

In comparison with the above, when a square of the wobble detectionsignal modulated by phase modulation is taken as shown in FIG. 86B, thesquared waveforms between an IPW area and an NPW area are produced to beidentical to each other. Thus, a portion such as a phase transition doesnot appear; a very stable signal is obtained; and a rise portion at theperiphery of the carrier signal shown in FIG. 87 is eliminated. As aresult, a signal of a carrier level of a single peak as shown in FIG. 88is obtained.

Now, a description will be given with respect to characteristics of theNBSNR measuring circuit shown in FIG. 84.

The band-pass filter circuit 1032 shown in FIG. 84 sets a centerfrequency of a band-pass filter to 697 kHz, and sets a Q value to 1.0.The squaring circuit shown in FIG. 84 sets a shutdown frequency (cutofffrequency) to be equal to or greater than 5.0 MHz.

A frequency f₀ shown in FIG. 89 corresponds to an original wobblefrequency shown in FIG. 86A, and a frequency 2 f ₀ shown in FIG. 89corresponds to a frequency after squared, shown in FIG. 86B. From ananalysis result of the spectrum analyzer 1034 shown in FIG. 84, Sp isdefined as follows. That is, a difference between a carrier level C (2 f₀) at the frequency 2 f ₀ and a carrier level C (f₀) at the frequency f₀shown in FIG. 89 is expressed as follows:Sp=C(2f ₀)−C(f ₀)

In the present embodiment, the above value of Sp is utilized to evaluatethe NBSNR measuring circuit shown in FIG. 84.

The carrier level of C (2 f ₀) and C (f₀) is calculated based on anaverage value using the spectrum analyzer 1034 of frequencies when aresolution bandwidth is 10 kHz. When the NBSNR of the input wobblesignal 1030 shown in FIG. 84 is 50 dB, there is a need for adjusting theNBSNR measuring circuit so that the value of Sp indicating thedifference from a carrier level of 697 kHz (f₀) is equal to or smallerthan −30 dB. In addition, when the NBSNR of the input wobble signal 1030is 30 dB, NBSNR of a square signal needs to be equal to or greater than23 dB. The resolution bandwidth of the spectrum analyzer 1034 shown inFIG. 84 is set to 10 kHz.

As described above, the present embodiment attains the followingadvantageous effects:

1) A ratio of a minimum value (Wppmin) of an amplitude of a wobbledetection signal with respect to (I1−I2)pp that is a track shiftdetection signal is set to 0.1 or more, whereby a sufficiently largewobble detection signal is obtained as compared with a dynamic range ofthe track shift detection signal. As a result, the detection precisionof the wobble detection signal can be taken significantly.

2) A ratio between a maximum value (Wppmax) of an amplitude of a wobbledetection signal and a minimum value (Wppmin) of an amplitude of awobble detection signal is set to 2.3 or less, whereby a wobble signalcan be stably detected without being greatly affected by a crosstalk ofa wobble from the adjacent track.

3) A value of NBSNR of a result obtained by squaring a wobble detectionsignal is allocated to be equal to or greater than 26 dB, whereby astable wobble signal having a high C/N ratio can be allocated, and thedetection precision of the wobble signal can be improved.

In the write-once type information storage medium according to thepresent embodiment, a recording mark is formed on a groove area, and aCLV recording system is employed. In this case, as described previously,a wobble slot position is shifted between the adjacent tracks, and thus,interference between the adjacent wobbles is likely to occur with awobble reproduction signal. In order to eliminate this effect, in thepresent embodiment, a contrivance is made to shift a modulation area sothat modulation areas do not overlap each other between the adjacenttracks.

Specifically, as shown in FIG. 73, a primary position 701 and asecondary position 702 can be set as an allocation location of amodulation area. Basically, assuming that after only the primarypositions 701 are allocated, there occurs a location in which modulationareas partially overlap between the adjacent tracks, the part of theprimary positions 701 are changed to the secondary positions 702. Forexample, in FIG. 73, when a modulation area of a groove area 505 is setas the primary position, a modulation area of the adjacent groove area502 and a modulation area of a groove area 506 partially overlap on eachother. Thus, the modulation area of the groove area 505 is set to thesecondary position. In this manner, there is attained advantageouseffect that a wobble address can be stably reproduced by preventing theinterference between the modulation areas of the adjacent tracks in areproduction signal from a wobble address.

The specific primary position and secondary position relating to amodulation area is set by switching an allocation location in the samewobble data unit. In the present embodiment, an occupying ratio of anon-modulation area is set to be higher than that of a modulation areaso that, the primary position and the secondary position can be switchedmerely by making a mere allocation change in the same wobble data unit.Specifically, in the primary position 701, as shown in FIGS. 71A and71C, the modulation area 598 is arranged at the start position in onewobble data unit. In the secondary position 702, as shown in FIGS. 71Band 71D, the modulation area 598 is arranged at the latter half positionin one of the wobble data units 560 to 571.

A coverage of the primary position 701 and the secondary position 702shown in FIGS. 71A to 71D, i.e., a range in which the primary positionor the secondary position continuously lasts is defined in the range ofphysical segments in the present embodiment. That is, as shown in FIGS.74B to 74D, there are provided three types (plural types) of allocationpatterns of modulation areas in the same physical segment. When thewobble signal detector unit 135 shown in FIG. 11 identifies anallocation pattern of a modulation area in a physical segment based onthe information contained in the type identification information 721 ona physical segment, the allocation location of another modulation area598 in the same physical segment can be predicted in advance. As aresult, there is attained advantageous effect that preparation fordetecting a next modulation area can be made, thus making it possible toimprove the precision of signal detection (judgment).

FIG. 74B shows allocation of wobble data units in a physical segment,wherein the number described in each frame indicates wobble data unitnumbers in the same physical segment. A 0-th wobble data unit isreferred to as a sync field 711 as indicated at the first row. A wobblesync area exists in a modulation area in this sync field 711. First toeleventh wobble data units are referred to as an address field 712.Address information is recorded in a modulation area included in thisaddress field 712. Further, in twelfth to sixteenth wobble data units,all of the wobble patterns are formed in an NPW unity field 713.

A mark “P” described in FIGS. 74B, 74C and 74D indicates that amodulation area is set to a primary position in a wobble data unit; anda mark “S” indicates that a modulation area is set to a secondaryposition in a wobble data unit. A mark “U” indicates that a wobble dataunit is included in the unity field 713, and a modulation area does notexist. An allocation pattern of a modulation area shown in FIG. 74Bindicates that all the areas in a physical segment are set to theprimary position; and an allocation pattern of a modulation area shownin FIG. 74C indicates all areas in a physical segment are set to thesecondary position. In FIG. 74D, the primary position and the secondaryposition are mixed in the same physical segment; a modulation area isset to the primary position in each of 0-th to fifth wobble data units,and a modulation area is set to the secondary position in each of sixthto eleventh wobble data units. As shown in FIG. 74D, the primarypositions and the secondary positions are half divided with respect toan area obtained by adding the sync field 711 and the address field 712,thereby making it possible to finely prevent an overlap of modulationareas between the adjacent tracks.

As shown in FIGS. 74A to 74D, in the present embodiment, there existthree types of setting locations of modulation areas in a physicalsegment on a write-once type information storage medium. Now, a specificdescription will be given below with respect to an example of setting amodulation area allocation type at each radial position on a write-oncetype information storage medium. A basic concept is described asfollows.

A purpose of type setting of a setting location in a basic modulationarea is to prevent modulation areas from overlapping in the adjacenttracks. The setting condition of modulation areas in the adjacent twotracks is shown in FIG. 107. Let us consider a case in which a startposition of an i-th track coincides with an n-th physical segment. Inthe write-once type information storage medium, a reference positionalong a circumference in one track can be arbitrarily set. Thus, in thei-th track, let us consider that a start position of n-th physicalsegment is a reference position (start position of an i-th track). Here,lowercase letters “i” and “n” each denote a positive number. Let usconsider that the i-th physical track is composed of j physical segmentsand that k wobble data units and m wobbles exist as fractional values.In this case, the lowercase letters “j”, “k”, and “m” each denote apositive value. If the values of “k” and “m” are not 0, the (n+j)-thphysical segment is allocated across the i-th track and an (i+1)-thtrack. An allocation relationship in modulation area between the i-thtrack and the (i+1)-th track is determined based on the value of “m”shown in FIG. 107.

As described above, in the i-th track, let us consider that a startposition of the n-th physical segment is a start position (referenceposition) of the i-th track and that modulation areas 94 only in theprimary setting location are set on the i-th track in the state shown inFIGS. 108A and 108B. In order to set the modulation areas between theadjacent tracks so as not to overlap on each other, allocation type 1 isselected as shown in FIG. 108A when “m” is 21 or more and is smallerthan 63, and the modulation area 94 in the primary setting location isset in the (i+1)-th track. In the other case, allocation type 2 is setas shown in FIG. 108B and a modulation area 95 in the secondary settinglocation is set in the (i+1)-th track.

In the case where allocation type 3 shown in FIG. 109 is set, a changepoint exists (is selected), the allocation type 1 is changed toallocation type 2 at the change point in one physical segment. In thecase where allocation type 3 is set, this type is selected under acondition relevant to the values of both of “m” and “k”. An example ofallocation type 3 is shown in FIG. 109, and allocation type 3 isselected when one of the conditions below is met.

1) “k” is 6 or more and smaller than 12 and “m” is 0 or more and smallerthan 21; or

2) “k” is 5 or more and smaller than 11 and “m” is 63 or more andsmaller than 84.

(Allocation type 3 is selected in the case where one of the aboveconditions 1 and 2 is met).

A specific method for selecting an allocation type in a modulation areais shown in a flow chart shown in FIG. 110. When selection of anallocation type in a modulation area is started (#81), wobble numberN_(W) for one cycle of a track (i-th track shown in FIGS. 107 to 109) atits inner periphery is first estimated at #82. A fractional number(value below decimal point) will appear as an actual wobble number for 1track. With respect to such an actual value, a truncating processingoperation of first digit after the decimal point is carried out; thetruncated value is approximated to a decimal function value; and a valueof N_(w) that is an integer value is found as “wobble number for 1track”. Next, the values “j”, “k”, and “m” defined in FIG. 107 arecalculated (#83). Here, a remainder value obtained by dividing “x” by“y” is defined as “x mod y”. Then, calculation of the values of “j”,“k”, and “m” is carried out at #83 by using each of the formulas below.j={N _(w)−(N _(w) mod 1428)}/1428m=N_(w) mod 84k={(N _(w) −m)/84 mod 17

Next, at #84, a type (from types 1 to 3 and a repetition number (from j,2 j, and j+1) are selected.

A type of physical segment selected under the above “k” and “m”conditions is as follows:

In the case of condition (1) where 21≦m<63, 2 j physical segments areselected as type 1 physical segments (refer to FIG. 74B).

In the case of condition (2) where 0≦k<6 and 0≦m<21 or 0≦k<5and 63≦m<84,j type 1 physical segments (refer to FIG. 74B) and j type 2 physicalsegments (refer to FIG. 74C) are selected.

In the case of condition (3) where 6≦k<12 and 0≦m<21 or 50≦k<11 and63≦m<84, j type 1 physical segments (refer to FIG. 74B), one type 3physical segment (refer to FIG. 74D), and j type 2 physical segments(refer to FIG. 74C) are selected.

In the case of condition (4) where 12≦k<17 and 0≦m<21 or 11≦m<17 and63≦m<84, j+1 type 1 physical segments (refer to FIG. 74B) and j+1 type 2physical segments (refer to FIG. 74C) are selected.

Further, the above-described processing operations at #82, #83, and #84are carried out with respect to all tracks; selections of all tracksterminate (#85); and then, selections of allocation types in modulationarea terminate (#86).

Now, a description will be given with respect to a method for recordingthe data segment data described previously with respect to the physicalsegment or the physical segment block in which address information isrecorded in advance by wobble modulation as described above. Data isrecorded in recording cluster units serving as units of continuouslyrecording data in both of a rewritable-type information storage mediumand a write-once type information storage medium. FIGS. 75A and 75B showa layout in this recording cluster. In recording clusters 540 and 542,one or more (integer numbers) of data segments continuously lasts, andan extended guard field 528 or 529 is set at the beginning or at the endof the segment. The extended guard fields 528 and 529 are set in therecording clusters 540 and 542 so as to be physically overlapped andpartially overwritten between the adjacent recording clusters so as notto produce a gap between the adjacent recording clusters when data isnewly additionally written or rewritten in units of the recordingclusters 540 and 542. As the position of each of the extended guardfields 528 and 529 set in the recording clusters 540 and 542, in theembodiment shown in FIG. 75A, the extended guard field 528 is arrangedat the end of the recording cluster 540. In the case where this methodis used, the extended guard field 528 follows a post amble area 526shown in FIG. 76A. Thus, in particular, in the write-once typeinformation storage medium, the post-amble area 526 is not mistakenlydamaged at the time of rewriting; the post-amble area 526 is protectedat the time of rewriting; and the reliability of position detectionusing the post amble area 526 at the time of data reproduction can beensured. As another embodiment, as shown in FIG. 75B, the extended guardfield 529 can also be arranged at the beginning of the recording cluster542. In this case, as is evident from a combination of FIG. 75B andFIGS. 76A to 76F, the extended guard field 529 immediately precedes aVFO area 522. Thus, at the time of rewriting or additional writing, theVFO area 522 can be sufficiently taken long, and thus, a PLL lead-intime relating to a reference clock at the time of reproduction of a datafield 525 can be taken long, making it possible to improve thereliability of reproduction of data recorded in the data field 525. Inthis way, since a recording cluster which is a rewriting unit is formedof one or more data segments, it is possible to facilitate a mixingrecording process with respect to the same information storage medium.PC data (PC files) of which a small amount of data is often rewrittenmany times and AV data (AV files) of which a large amount of data iscontinuously recorded one time. That is, with respect to data used for apersonal computer, a comparatively small amount of data is oftenrewritten many times. Therefore, a recording method suitable for PC datais obtained by minimally setting data units of rewriting or additionalwriting. In the present embodiment, as shown in FIG. 56, an ECC block iscomposed of 32 physical sectors. This, a minimum unit for efficientlycarrying out rewriting or additional writing is obtained by carrying outrewriting or additional writing in data segment units including only oneECC block. Therefore, a structure in the present embodiment in which oneor more data segments are included in a recording cluster which is arewriting unit or an additional writing unit is obtained as a recordingstructure suitable for PC data (PC files). In AV (Audio Video) data, itis necessary to continuously record a very large amount of video imageinformation and voice information smoothly without any problem. In thiscase, continuously recorded data is collectively recorded as onerecording cluster. At the time of AV data recording, when a random shiftamount, a structure in a data segment, or a data segment attribute andthe like is switched on a data segment by segment basis configuring onerecording cluster, a large amount of time is required for such aswitching process, making it difficult to carry out a continuousrecording process. In the present embodiment, as shown in FIGS. 75A and75B, it is possible to provide a recording format suitable for AV datarecording for continuously recording a large amount of data byconfiguring a recording cluster while data segments in the same format(without changing an attribute or a ransom shift amount and withoutinserting specific information between data segments) are continuouslyarranged. In addition, a simplified structure in a recording cluster isachieved, and simplified recording control circuit and reproductiondetector circuit are achieved, making it possible to reduce the price ofan information recording/reproducing apparatus or an informationreproducing apparatus. A data structure in recording cluster 540 inwhich data segments (excluding the extended guard field 528) in therecording cluster shown in FIGS. 75A and 75B are continuously arrangedis completely identical to those of the read-only information storagemedium shown in FIG. 66B and the write-once type information storagemedium shown in FIG. 66C. In this way, a common data structure isprovided among all of the information storage mediums regardless of theread-only type, the write-once type, or the rewritable-type, thusallocating medium compatibility. In addition, a detector circuit of theinformation recording/reproducing apparatus or the informationreproducing apparatus whose compatibility has been arranged can be usedin common; high reliability of reproduction can be arranged; and pricereduction can be achieved.

By employing the structure shown in FIGS. 75A and 75B, random shiftamounts of all the data segments inevitably coincide with each other inthe recording cluster. In the rewritable-type information medium, arecording cluster is recorded by random shifting. In the presentembodiment, the random shift amounts of all the data segments coincidewith each other in the same recording cluster 540. Thus, in the casewhere reproduction has been carried out across the different datasegments from each other in the same recording cluster 540, there is noneed for synchronization adjustment (phase resetting) in a VFO area(reference numeral 522 in FIG. 76D), making it possible to simplify areproduction detector circuit at the time of continuous reproduction andto allocate high reliability of reproduction detection.

FIGS. 76A to 76F show a method for recording data to be rewritablyrecorded in a rewritable-type information storage medium. Now, althougha description will be given while focusing on a rewritable-typeinformation storage medium, it should be noted that an additionalwriting method relevant to a write-once type information storage mediumis basically identical to the above recording method. A layout in therecording cluster in a write-once type information storage mediumaccording to the present embodiment will be described in way of exampleemploying a layout shown in FIG. 75A. The present embodiment is notlimited thereto, and a layout shown in FIG. 75B may be employed for arewritable-type information storage medium. In the present embodiment,rewriting relating to rewritable data is carried out in units of therecording clusters 540 and 541 shown in FIGS. 76B and 76E. As describedlater, one recording cluster is composed of one or more data segments529 to 531 and an extended guard field 528 arranged at the end. That is,the start position of one recording cluster 631 coincides with that ofthe data segment 531, and the cluster starts from the VFO area 522. Inthe case where a plurality of data segments 529 and 530 are continuouslyrecorded, the plurality of data segments 529 and 530 are continuouslyarranged in the same recording cluster 531. In addition, the buffer area547 which exists at the end of the data segment 529 and the VFO area 532which exists at the beginning of a next data segment continuously last,and thus, a phase (of a recording reference clock) at the time ofrecording) between these areas coincides with one another. Whencontinuous recording terminates, an extended guard area 528 is arrangedat the end position of the recording cluster 540. The data size of thisextended guard area 528 is equal to the size for 24 data bytes as databefore modulated.

As is evident from a correlation between FIGS. 76A and 76C,rewritable-type guard areas 461 and 462 each include: post amble areas546 and 536; extra areas 544 and 534; buffer areas 547 and 537; VFOareas 532 and 522; and pre-sync areas 533 and 523, and an extended guardfield 528 is arranged only in location in which continuous recordingterminates. The present embodiment is featured in that rewriting oradditional writing is carried out so that the extended guard area 528and the succeeding VFO area 522 partially overlap each other at aduplicate site 591 at the time of rewriting. By rewriting or additionalwriting while partial duplication is maintained, it is possible toprevent a gap (area in which no recording mark is formed) from beingproduced between the recording clusters 540 and 541. In addition, astable reproduction signal can be detected by eliminating inter-layercross talk in an information storage medium capable of carrying outrecording in a single-sided double recording layer.

The data size which can be rewritten in one data segment in the presentembodiment is 67+4+77376+2+4+16=77469 (data bytes). One wobble data unit560 is 6+4+6+68=84 (wobbles). One physical segment 550 is composed of 17wobble data units, and a length of seven physical segments 550 to 556coincides with that of one data segment 531. Thus, 84×17×7=9996(wobbles) are arranged in the length of one data segment 531. Therefore,from the above formula, 77496/9996=7.75 (data bytes/wobble) correspondsto one wobble.

As shown in FIG. 77, an overlap portion of the succeeding VFO area 522and the extended guard field 528 follows 24 wobbles from the startposition of a physical segment, and the starting 16 wobbles of aphysical segment 550 are arranged in a wobble sync area 580, and thesubsequent 68 wobbles are arranged in a non-modulation area 590.Therefore, an overlap portion of the VFO area 522 which follows 24wobbles and the extended guard field 528 is included in thenon-modulation area 590. In this way, the start position of a datasegment follows the 24 wobbles from the start position of a physicalsegment, whereby the overlap portion is included in the non-modulationarea 590. In addition, a detection time and a preparation time forrecording process of the wobble sync area 580 can be sufficiently taken,and thus, a stable and precise recording process can be guaranteed.

A phase change recording film is used as a recording film of therewritable-type information storage medium in the present embodiment. Inthe phase change recording film, degradation of the recording filmstarts in the vicinity of the rewriting start/end position. Thus, ifrecording start/recording end at the same position is repeated, thereoccurs a restriction on the number of rewritings due to the degradationof the recording film. In the present embodiment, in order to alleviatethe above described problem, at the time of rewriting, J_(M+1)/12 databytes are shifted as shown in FIG. 77, and the recording start positionis shifted at random.

Although the start position of the extended guard field 528 coincideswith that of the VFO area 522 in order to explain a basic concept inFIGS. 76C and 76D, strictly, the start position of the VFO area 522 isshifted at random, as shown in FIG. 77, in the present embodiment.

A phase change recording film is used as a recording film in a DVD-RAMdisc which is a current rewritable-type information storage medium aswell, the start/end positions of recording is shifted at random for thepurpose of improving the rewriting count. The maximum shift amount rangewhen random shifting has been carried out in the current DVD-RAM disc isset to 8 data bytes. A channel bit length (as data after modulated, tobe recorded in a disc) in the current DVD-RAM disc is set to 0.143 μm onaverage. In the rewritable-type information storage medium according tothe present embodiment, an average length of channel bits is obtained as(0.087+0.093)/2=0.090 (μm) as shown in FIG. 34. In the case where alength of a physical shift range is adjusted to conform with the currentDVD-RAM disc, by using the above value, the required minimal lengthserving as a random shift range in the present embodiment is obtainedas:

8 bytes×(0.143 μm/0.090 μm)=12.7 bytes

In the present embodiment, in order to allocate easiness of areproduction signal detecting process, the unit of random shift amounthas been adjusted to conform with “channel bits” after modulated. In thepresent embodiment, ETM modulation (Eight to Twelve modulation) forconverting 8 bits to 12 bits is used, and thus, formula expression whichindicates a random shift amount is designated by J_(m)/12 (data bytes)while a data byte is defined as a reference. Using the value of theabove formula, a value which can be taken by J_(m) is 12.7×12=152.4, andthus, J_(m) ranges 0 to 152. For the above described reason, in therange meeting the above formula, a length of the random shift rangecoincides with the current DVD-RAM disc, and the rewriting count similarto the current DVD-RAM disc can be guaranteed. In the presentembodiment, a margin is slightly provided with respect to the requiredminimal length in order to allocate the current or more rewriting count,and the length of the random shift range has been set to 14 (databytes). From these formulas, 14×12=168 is established, and thus, a valuewhich can be taken by J_(m) has been set in the range of 0 to 167. Asdescribed above, the random shift amount is defined in a range which iswider than J_(m)/12 (0≦J_(m)≦154), whereby a length of a physical rangerelevant to the random shift amount coincides with that of the currentDVD-RAM. Thus, there is attained advantageous effect that the repetitionrecording count similar to that of the current DVD-RAM can beguaranteed.

In FIG. 76C, the lengths of the buffer area 547 and the VFO area 532 inthe recording cluster 540 become constant. As is evident from FIG. 75Aas well, the random shift amount J_(m) of all the data segments 529 isobtained as the same value everywhere in the same recording cluster 540.In the case of continuously recording one recording cluster 540 whichincludes a large amount of data segments, a recording position ismonitored from a wobble. That is, a position of the wobble sync area 580shown in FIGS. 72A to 72D is detected, and, in the non-modulation areas592 and 593 shown in FIGS. 71C and 71D, the check of the recordingposition on the information storage medium is made at the same time asrecording while the number of wobbles is counted. At this time, a wobbleslip (recording at a position shifted by one wobble cycle) occurs due tomistaken wobble count or rotation non-uniformity of a rotary motor whichrotates the information storage medium, and the recording position onthe information storage medium is rarely shifted. The informationstorage medium according to the present embodiment is featured in that,in the case where a recording position shift generated as describedabove has been detected, adjustment is made in the rewritable-type guardarea 461 shown in FIGS. 76A to 76F, and recording timing correction iscarried out in the guard area 461. Now, an H format will be describedhere. This basic concept is employed in a B format, described later. InFIGS. 76A to 76F, although important information for which bit missingor bit duplication cannot be allowed is recorded in a postamble area546, an extra area 544, and a pre-sync area 533, a specific pattern isrepeated in the buffer area 547 and the VFO area 532. Thus, as long asthis repetition boundary position is arranged, missing or duplication ofonly one pattern is allowed. Therefore, in the present embodiment, inparticular, adjustment is made in the buffer area 547 or the VFO area532, and recording timing correction is carried out.

As shown in FIG. 77, in the present embodiment, an actual start pointposition defined as a reference of position setting is set so as tomatch a position of wobble amplitude “0” (wobble center). However, theposition detecting precision of a wobble is low, and thus, in thepresent embodiment, the actual start point position allows a shiftamount up to a maximum of ±1data byte”, as “±1 max” in FIG. 77 isdescribed.

In FIGS. 76A to 76F and 77, the random shift amount in the data segment530 is defined as J_(m) (as described above, the random shift amounts ofall the data segments 529 coincide with each other in the recordingcluster 540); and the random shift amount of the data segment 531 to beadditionally written is defined as J_(m+1) As a value which can be takenby J_(m) and J_(m+1) shown in the above formula, for example, when anintermediate value is taken, J_(m)=J_(m+1)=84 is obtained. In the casewhere the positional precision of an actual start point is sufficientlyhigh, the start position of the extended guard field 528 coincides withthat of the VFO area 522, as shown in FIGS. 76A to 76F.

In contrast, after the data segment 530 is recorded at the maximum backposition, in the case where the data segment 531 to be additionallywritten or rewritten has then been recorded in the maximum frontposition, the start position of the VFO area 522 may enter a maximum 15data bytes in the buffer area 537. Specific important information isrecorded in the extra area 534 that immediately precedes the buffer area537. Therefore, in the present embodiment, a length of the buffer area537 requires 16 data bytes or more. In the embodiment shown in FIGS. 76Ato 76F, a data size of the buffer area 537 is set to 15 data bytes inconsideration of a margin of one data byte.

As a result of a random shift, if a gap occurs between the extendedguard area 528 and the VFO area 522, in the case where a single-sideddouble recording layer structure has been employed, there occurs aninter-layer crosstalk at the time of reproduction due to that gap. Thus,even if a random shift is carried out, a contrivance is made such thatthe extended guard field 528 and the VFO area 522 partially overlap eachother, and a gap is not produced. Therefore, in the present embodiment,it is necessary to set the length of the extended guard field 528 to beequal to or greater than 15 data bytes. The succeeding VFO area 522sufficiently takes 71 data bytes. Thus, even if an overlap area of theextended guard field 528 and the VFO area 522 slightly widens, there isno obstacle at the time of signal reproduction (because a time forobtaining synchronization of reproduction reference clocks issufficiently arranged in the VFO area 522 which does not overlap).Therefore, it is possible to set the value of the extended guard field528 to be greater than 15 data bytes. As has already been described, awobble slip rarely occurs at the time of continuous recording, and arecording position may be shifted by one wobble cycle. One wobble cyclecorresponds to 7.75 (≅8) data bytes, and thus, in the presentembodiment, a length of the extended guard field 528 is set to equal toor greater than 23 (=15+8) data bytes. In the embodiment shown in FIGS.76A to 76F, like the buffer area 537, the length of the extended guardfield 528 is set to 24 data bytes in consideration of a margin of onedata byte similarly.

In FIG. 76E, it is necessary to precisely set the recording startposition of the recording cluster 541. The informationrecording/reproducing apparatus according to the present embodimentdetects this recording start position by using a wobble signal recordedin advance in the rewritable-type or write-once type information storagemedium. As shown in FIGS. 71A to 71D, in all areas other than the wobblesync area 580, a pattern changes from NPW to IPW in units of fourwobbles. In comparison, in the wobble sync area 580, wobble switchingunits are partially shifted from four wobbles, and thus, the wobble syncarea 580 can detect a position most easily. Thus, the informationrecording/reproducing apparatus according to the present embodimentdetects a position of the wobble sync area 580, and then, carries outpreparation for a recording process, and starts recording. Thus, it isnecessary to arrange a start position of a recording cluster 541 in anon-modulation area 590 immediately after the wobble sync area 580. FIG.77 shows the contents of the allocation. The wobble sync area 580 isarranged immediately after switching position of a physical segment. Thelength of the wobble sync area 580 is defined by 16 wobble cycles.Further, after detecting the wobble sync area 580, eight wobble cyclesare required for preparation for the recording process in considerationof a margin. Therefore, as shown in FIG. 77, even in consideration of aransom shift, it is necessary that the start position of the VFO area522 which exists at the start position of the recording cluster 541 isarranged rearward by 24 wobbles or more from a switching position of aphysical segment.

As shown in FIGS. 76A to 76F, a recording process is carried out manytimes in a duplicate site 591 at the time of rewriting. When rewritingis repeated, a physical shape of a wobble groove or a wobble landchanges (is degraded), and the wobble reproduction signal amount islowered. In the present embodiment, as shown in FIG. 76F, a contrivanceis made so that a duplicate site 591 at the rewriting or at the time ofadditional writing is recorded in the non-modulation area 590 instead ofarriving in the wobble sync area 580 or wobble address area 586. In thenon-modulation area 590, a predetermined wobble pattern (NPW) is merelyrepeated. Thus, even if a wobble reproduction signal amount is partiallydegraded, interpolation can be carried out by utilizing the precedingand succeeding wobble reproduction signals. In this way, the position ofthe duplicate site 591 at the rewriting or at the time of additionalwriting has been set so as to be included in the non-modulation area590. Thus, there occurs advantageous effect that a stable wobbledetection signal from the wobble address information 610 can beguaranteed while preventing degradation of the wobble reproductionsignal amount due to the shape degradation in the wobble sync area 580or wobble address area 586.

Now, FIG. 78 shows an embodiment of a method for additionally writing awrite-once type data recorded on a write-once type information storagemedium. A position rearward of 24 wobbles is defined as a writing startpoint from the boundary position of physical segment blocks. Withrespect to data to be newly additionally written, after a VFO area for71 data bytes has been formed, a data area (data field) in an ECC blockis recorded. This writing start point coincides with an end position ofthe buffer area 537 of recording data recorded immediately before thewriting. The backward position at which the extended guard field 528 hasbeen formed by a length for eight data bytes is obtained as a recordingend position of additional writing data (writing end point). Therefore,in the case where data has been additionally written, the data for eightdata bytes is recorded to be duplicated at a portion of extended guardfield 529 recorded just before and the VFO area to be newly additionallywritten.

FIG. 111 is a flow chart illustrating an outline of procedures forrecording information in a medium (such as an HD DVD-R disc) includinginformation such as recording management data field 1 (RMD Field1). Forexample, in the case where information is recorded in a disc 221 shownin FIG. 31, information is recorded in part of a lead-in area (such as adrive test zone shown in FIGS. 35A to 35C to FIGS. 38A to 38C) or a dataarea (#100), and then, information (Drive specific data DSD1 to DSD4) isrecorded in a recording management field or the like (such as RMD Field1shown in FIG. 113) (#102).

FIG. 112 is a flow chart illustrating an outline of procedures forreproducing information from a medium (such as an HD DVD-R disc) havingrecorded therein information contained in the recording management datafield 1 or the like (RMD Field1). For example, in the case whereinformation is reproduced from the disc 221 shown in FIG. 31,information is reproduced from the recording management field or thelike (#200), and then, information is reproduced from the data area orthe like (#202).

FIG. 113 is a view showing detailed information stored in the recordingmanagement data field 1 (RMD Field1). This data field 1 (RMD Field1)contains OPC relevant information. In the RMD Field1, OPC relevantinformation on a maximum of 4 drives that can be shared (such as RunningOptimum Power Control information) can be recorded. In the case of asingle drive, OPC relevant information is recorded in the first internalfield #1 of data field 1, and “00h” is set in the remaining 3 internalfields #2 to #4. In any case, “00h” is set in an unused field containedin RMD Field1.

OPC relevant information for a new drive is always recorded in the firstinternal field #1 of data field 1. If a current RMD field #1 has alreadybeen used, and drive information (drive manufacturer ID, serial number,and model name) cannot be specified for that new drive, the informationcontained in the current RMD fields #1 to #3 is copied to field #2 to #4of the new drive, and the information contained in the current RMD field#4 is ignored.

The first internal field #1 (byte positions BP0 to BP255) of data field1 shown in FIG. 113 stores drive manufacturer ID, serial number, modelname, time stamp, inner test zone address, outer test zone address,running OPC (optimum power control) information, DSV (Digital SumValue), drive specific information (Drive specific data) DSD1 and thelike.

The second internal field #2 (byte positions BP256 to BP511) of datafield 1 stores information items similar to those contained in datafield 1 (Drive specific information “Drive specific data” is referred toas DSD2). The third internal field #3 of data field 1 (byte positionsBP512 to BP767) stores information items similar to those contained indata field 1 (Drive specific information “Drive specific data” isreferred to as DSD3). The fourth internal field #4 of data field 1 (bytepositions BP768 to BP1023) stores information items similar to thosecontained in data field 1 (Drive specific information “Drive specificdata” is referred to as DSD4).

While any item of data specific to a drive to be used may be writteninto “Drive specific data” DSD1 stored at the byte positions BP128 toBP191; “Drive specific data” DSD2 stored at the byte positions BP384 toBP447; “Drive specific data” DSD3 stored at the byte positions BP640 toBP703; and “Drive specific data” DSD4 stored at the byte positions BP896to BP959, information on Write Strategy described with reference to FIG.18 is provided as one example of such specific data. When “00h” iswritten in the fields of DSD1 to DSD4, these fields are invalid. Whenany data other than “00h” is written, the items of data written in theabove DSD fields are updated in ascending order of the DSD number.

The above description mainly relates to a single-sided single-layerdisc. The following description relates to a single-sided multi-layer(herein, dual layer) disc. The same portions as those of the abovedescription will be indicated in the same reference numerals and theirdetailed description will be omitted.

Measurement Condition

The characteristics of a recording medium are determined in accordancewith DVD specifications, and it is necessary to test whether thespecifications are satisfied or not before selling the recording medium.For that purpose, a device for measuring characteristics of a recordingmedium is required, and measurement conditions of a measuring device aredetermined in the specifications. Characteristics of an optical head formeasuring characteristics of a medium are regulated as follows.

Wavelength λ: 405±5 nm

Polarization: circularly polarized light

Polarizing Beam Splitter PBS: Shall be used.

Numerical aperture: 0.65±0.01

Light intensity at the rim of the pupil of the objective lens: 55% to70% of the maximum intensity level

Wave front aberration after passing through an ideal substrate: 0.033λmax

A Normalized detector size on a disc: 100<A/m2<144 μm, in which

A: the central detector area of the optical head

M: the transversal magnification from disc to detector

Relative intensity noise (RIN)* of laser diode: −125 dB/Hz (max).

*: RIN (dB/Hz)=10 log [(AC power density/Hz)/DC power

Cross-sectional structure of single-sided dual layer recordable disc

FIG. 117 shows a cross-sectional view of a single-sided dual layerrecordable disc (write-once disc). The single-sided dual layer disc hasthe first transparent substrate 2-3 made of polycarbonate at the side ofan incident plane (read surface) of a laser beam 9 emitted from anobjective lens. The first transparent substrate 2-3 has transparency fora wavelength of a laser beam. A wavelength of the laser beam is 405 (±05) nm.

A first recording layer (Layer 0) 3-3 is provided on a plane opposite tothe light incident plane of the first transparent substrate 2-3. Pitscorresponding to recording information are provided to the firstrecording layer 3-3. An optical semi-transparent layer 4-3 is providedon the first recording layer 3-3.

A space layer 7 is provided on the optical semi-transparent layer 4-3.The space layer 7 serves as a transparent substrate with respect toLayer 1, and has transparency for a wavelength of a laser beam.

A second recording layer (Layer 1) 3-4 is provided on a plane oppositeto the optical incident plane of the space layer 7. Pits correspondingto recording information are provided to the second recording layer 3-4.An optical reflection layer 4-4 is provided on the second recordinglayer 3-4. A substrate 8 is provided on the optical reflection layer4-4.

Thickness of Space Layer 7

A thickness of the space layer 7 in the single-sided dual layerwrite-once disc is 25.0±5.0 μm. If it is thinner, interlayer crosstalkis made greater, which makes it difficult to manufacture, and therefore,a measure of thickness is regulated. In a single-sided dual layerread-only recording medium, a thickness of the space layer 7 is 20.0±5.0μm. Because a write-once recording medium is under the influence ofinterlayer crosstalk greater than the case of a read-only recordingmedium, the single-sided dual layer write-once disc is made thicker toslight extent as compared with the read-only recording medium, and acenter value of the thickness of the space layer 7 is regulated to be 25μm or more.

Interferometer Method

A method for measuring a thickness of the space layer 7 is a methodcalled interference analysis, and the general outline thereof is shownin FIGS. 118A and 118B. As shown in FIG. 118A, a light is made incidentinto a single-sided dual layer disc, and lights R1 and R2 reflecting onboundary surfaces at the both sides (the upper side and the lower side)of the space layer are measured. The incident light is, as shown in FIG.118B, changed in its wavelength. A thickness d of the space layer 7 isdetermined as follows by measuring a phase difference between thereflected lights R1 and R2:d=λ1·λ2/2n(λ2−λ1)where n is a refractive index of the space layer.

Reflectivity Including Birefringence

Reflectivity in the system lead-in area and system lead-out area is 4.2to 8.4% for Low-to-High disc.

Reflectivity in the data lead-in area, data area, middle area, and datalead-out area is 4.5 to 9.0% for Low-to-High disc.

The higher the reflectivity, the better. However, there are limitsthereto, and those are determined such that the number of times ofrepeat reproduction and characteristics of a reproduction signal satisfypredetermined standards. Because the recording layer serving as Layer 0must be semi-transparent, a refractivity thereof is lower than that of asingle layer.

As described above, a single-sided multilayer recording medium has theproblem (interlayer crosstalk) that reflected lights from other layershave an effect on a reproduction signal. To described in detail, when arecorded status of a signal of the other layer (for example, Layer 0) tobe irradiated with the reproduction beam is changed during reproductionof one layer (for example, Layer 1), the problem that a signal of Layer1 during reproduction is offset by the crosstalk is brought about.Further, when a signal is recorded on Layer 1, an optimum recordingpower varies depending on whether Layer 0 has been recorded orunrecorded. These problems result from, for example, the fact that thetransmittance and the reflectivity of the recording medium with Layer 0vary in accordance with a recorded status or an unrecorded status, orthat a thickness of the space layer cannot be made much greater in orderto reduce an optical aberration. However, it is extremely difficult tophysically reduce such characteristics. Then, an optical disc of thepresent embodiment has a feature that no offset in a signal is broughtabout by providing clearance (areas in constant recorded status) torespective layers.

Definition of the Clearance

In a dual layer disc, the bundle of light that is focused onto a layerof the disc spreads out on the other layer of the disc and reflects atthe other layer as well as the layer where the light focuses, as shownin FIG. 119. Thus, reading and writing of a layer are affected by theinfluence of the beam that is reflected at the other layer of the disc.To mitigate this influence, the status of the other layer of the discshould be uniform in terms of existence of recorded marks. The area thataffects the quality of reading and writing of a layer is defined on theother layer of the disc taking the focused point as a reference. Then,reading and writing at a point on a layer should be qualified by keepingthe area on the other layer of the disc uniform. The radial distance ofthe area is called “Clearance”. Refer to FIG. 120.

The Clearance is calculated considering three elements, the maximumrelative deviation of the radius between Layer 0 and Layer 1, themaximum relative radial run-out between Layer 0 and Layer 1 and theradius of the ray bundle on the other layer. These values are defined asfollows;

Maximum relative deviation of the radius between Layer 0 and Layer 1:Rd_(max)=40 μm

Maximum relative radial run-out between Layer 0 and Layer 1:Rr _(max)=(40+60)/2=50 μm

The theoretical radius of the ray bundle on the other layer:R _(c) _(—) _(theoretical) =T _(sl)×tan(sin⁻¹(NA/n))=14 μmwhere T_(sl) the maximum thickness of the space layer 30 μm, NA isnumerical aperture=0.65 and n is refractive index of the space layer1.5.

The practical radius, R_(c) _(—) _(principal) can be supposed to beabout 10 μm effectively, because the intensity of the ray bundle ishighest in the center and lowest in the rim.

The Clearance Cl of the disc is calculated by the following equation:Cl=Rd _(max) +Rr _(max) +R _(c) _(—) _(practical)=100 μm

The Information area format is constructed considering the clearance atthe edges of the areas in the Information area.

Note: FIG. 120 illustrates a concept of the position shifts.

The relative deviation of the radius doesn't necessarily cause anoutward shift in Layer 1, and the relative radial run-out doesn'tnecessarily cause a inward shift in Layer 0.

Example of the Clearance in the Number of Physical Sectors

It is useful to simplify the Clearance in the number of Physical sectorsfrom a viewpoint of compatibility. A_(M) in FIG. 121 should be used forthe clearance in the number of Physical sectors at the location of M(Refer to FIG. 122).

FIG. 122 shows a physical sector number PSN of Layer 0 and a recordablephysical sector of Layer 1 corresponding to the physical sector numberPSN. The physical sector numbers of Layer 0 and Layer 1 have a bitinverted relation.

Measuring Method of the Relative Deviation of the Radius between Layer 0and Layer 1

A microscope with a two-dimensional measurement system that is capableof measuring a radius of a circle by locating three points on the circleshould be used to verify the relative deviation of the radius betweenLayer 0 and Layer 1 of a disc.

The procedure to verify the relative deviation of the radius betweenLayer 0 and Layer 1 of a disc is as follows.

1) Data should be recorded on Layer 0 and Layer1 for more than 1000tracks each. The last recorded PSN on Layer 0 should be A. The recordingon Layer 1 should be started at the PSN A-R. R is the number of Physicalsectors, which is chosen to make the measurement by the microscopeeasily. Refer to FIG. 123.

2) Three points on the outer edge of the recorded area should bemeasured on the microscope by the two-dimensional measuring system foreach layer.

3) The radius of the outer-rim circle is calculated from the above threepoints for each layer. The r_(A) _(—) _(measured) and r_(A) _(—) _(R)_(—) _(measured) are the calculated values for Layer 0 and Layer 1respectively.

4) The relative deviation rd of the radius between Layer 0 and Layer 1is calculated by the following equation.r _(d) =|r _(A) _(—) _(measured) −r _(A-R) _(—) _(measured) r _(R)|where r_(R) is a radial distance that originates from the difference ofPSNs at the edges of the recorded areas on the both layers and iscalculated by R and r_(A) _(—) _(measured).

The reference values of A, R and r_(R) are listed in FIG. 123.

General Parameters

General parameters of single-sided dual layer write-once disc is shownin FIG. 124. These parameters are similar to the general parameters ofsingle-sided single layer write-once disc shown in FIG. 33. Followingsare different from those of FIG. 33; user data capacity (30 GB), dataarea inner radius (24.6 mm for Layer 0, 24.7 mm for Layer 1), and dataarea outer radius (58.1 mm for Layers 0 and 1).

Information Area Format

The information area is divided into 7 parts: the System Lead-in area,Connection area, Data Lead-in area, Data area, Middle area, DataLead-out area, and System Lead-out area. There is only one informationarea extending over two layers. The Middle area on each layer allows theread-out beam to move from Layer 0 to Layer 1. Refer to FIG. 130. TheData area is intended for recording of the main data. The System Lead-inarea contains the Control data and Reference code. The Data Lead-outarea allows for a continuous smooth read-out.

Track Structure

The System Lead-in area and System Lead-out area contain tracks whichconsist of a series of embossed pits. A track in System Lead-in area andSystem Lead-out area forms a 360° turn of a continuous spiral. Thecenter of the track is the center of the pits.

A track from Data Lead-in area to Middle area on Layer 0 and that fromMiddle area to Data Lead-out area on Layer 1 form a 360° turn of acontinuous spiral.

The Data Lead-in area, Data area and Middle area on Layer 0, and theMiddle area, Data area and Data Lead-out area on Layer 1 consist of aseries of groove tracks. The groove tracks are continuous from the startof the Data Lead-in area to the end of the Middle area on Layer 0 andthe start of the Middle area to the end of the Data Lead-out area onLayer 1. If two single-sided single layer discs are pasted on eachother, a double-sided dual layer disc having two read-out surfaces ismanufactured.

Layer is to be defined against the one read-out side of the disc. An HDDVD-R for dual layer disc has two layers identified as Layer 0 and Layer1 per read-out side. Layer 0 is the layer nearest to the read-outsurface and Layer 1 is the layer farthest to the read-out surface.

HD DVD-R for dual layer discs can be single-sided or double-sided. Fordouble-sided discs there are four layers. Two layers of each side areaccessed individually through the opposite sides of the disc.

Direction of Rotation

The disc rotates counterclockwise as viewed from the read-out side. Thetrack spirals outward from the inner diameter to the outer diameter onLayer 0. The track spirals inward from the outer diameter to the innerdiameter on Layer 1.

Track Layout

Each track in the System Lead-in area and System Lead-out area isdivided into Data segments. Each track in the data Lead-in area, dataarea, data Lead-out area, and middle area is divided into PS (PhysicalSegment) blocks. Each PS block should be divided into seven physicalsegments. Each Physical segment comprises 11067 bytes.

Lead-in area, Lead-out area and Middle area

The schematic of the Lead-in area and the Lead-out area is shown in FIG.125. The schematic of the original Middle area on Layer 0 and Layer 1 isshown in FIG. 126. The layout of the Middle area can be changed byMiddle area expansion. FIG. 126 shows an original Middle area beforeexpansion. The border of each zone and each area in Lead-in area,Lead-out area and Middle area coincides with the border of Datasegments.

A system lead-in area, a connection area, a data lead-in area, and adata area are provided in sequence from the innermost periphery at theinner peripheral side of Layer 0. A system lead-out area, a connectionarea, a data lead-out area, and a data area are provided in sequencefrom the innermost periphery at the inner peripheral side of Layer 1. Inthis way, because the data lead-in area including a management area isprovided to only Layer 0, information on the layer L1 are also writteninto the data lead-in area of the Layer 0 at the time of finalizing onLayer 1. As a consequence, all the management information can beobtained by merely reading Layer 0 on start-up, and there is theadvantage that there is no need to read Layer 0 and Layer 1 one by one.Note that, in order to record data on Layer 1, the whole Layer 0 must bewritten. The management area is to be filled at the time of finalizingthe disc.

The system lead-in area of Layer 0 is composed of an initial zone, abuffer zone, a control data zone, and a buffer zone in sequence from theinner peripheral side. The data lead-in area of Layer 0 is composed of ablank zone, a guard track zone, a drive test zone, a disc test zone, ablank zone, an RMD duplication zone, an L-RMD (recording management zonein Data Lead-in area), an R-physical format information zone, and areference code zone in sequence from the inner peripheral side. Astarting address (inner peripheral side) of the data area of Layer 0 andan ending address (inner peripheral side) of the data area of Layer 1are shifted by a distance of a clearance, and the ending address (innerperipheral side) of the data area of Layer 1 is at a side outer than thestarting address (inner peripheral side) of the data area of Layer 0.

The data lead-out area of Layer 1 is composed of a blank zone, a disctest zone, a drive test zone, and a guard track zone in sequence fromthe inner peripheral side.

The blank zone is a zone having grooves, but having no data recordedthereon. The guard track zone is a zone on which a specific pattern fora test is recorded, and unmodulated data “00” is recorded thereon. Theguard track zone of Layer 0 is provided for recording onto the disc testzone and the drive test zone of Layer 1. Therefore, the guard track zoneof Layer 0 corresponds to a range obtained by adding at least clearanceto the disc test zone and the drive test zone of Layer 1. The guardtrack zone of Layer 1 is provided for recording onto the drive testzone, the disc test zone, the blank zone, the RMD duplication zone, theL-RMD, the R-physical format information zone, and the reference codezone of Layer 0. Therefore, the guard track zone of Layer 1 correspondsto a range obtained by adding at least clearance to the drive test zone,the disc test zone, the blank zone, the RMD duplication zone, the L-RMD,the R-physical format information zone, and the reference code zone ofLayer 0.

As shown in FIG. 126, both the middle areas of Layer 0 and Layer 1 eachare composed of the guard track zone, the drive test zone, the disc testzone, and the blank zone in sequence of the inner peripheral side. Theguard track zone of Layer 0 is provided for recording onto the drivetest zone and the disc test zone of Layer 1. Therefore, an endingposition of the guard track zone of Layer 0 is positioned at an outerperipheral side by at least a distance of a clearance from a startingposition of the disc test zone of Layer 1. The blank zone of Layer 1 isprovided for recording onto the drive test zone and the disc test zoneof Layer 0. Therefore, an ending position of the blank zone of Layer 1is positioned at an inner peripheral side by at least a distance of aclearance from a starting position of the drive test zone of Layer 0.

In the present embodiment, an opposite track path as shown in FIG. 127is used in order to maintain the continuity of recording from Layer 0 toLayer 1. In sequential recording, the routine does not proceed torecording onto Layer 1 unless recording onto Layer 0 is completed.

Example of Data Recording Procedures

The data recording in a disc basically proceeds from Layer 0 to Layer 1.An example of data recording procedure from the Initialization to theFinalization is shown in FIGS. 128A to 129C.

FIG. 128A shows the zone structure of the Information area. Some of thezones that occupy a few tracks and don't significantly affect therecording procedure have been eliminated from the figure.

FIG. 128B shows the process from the Initialization to the user datarecording on Layer 0. An arrow indicates a recording direction. Therecording is performed in the following order.

1) Drive test zone (Layer 0)

2) RMD duplication zone

3) Inner Guard track zone (Layer 0, padded)

4) L-RMZ

5) Data area (Layer 0)

6) Drive test zone (Layer 0)

7) Data area (Layer 0)

8) L-RMZ

Note that 6) to 8) are repeated by X times.

FIG. 128C shows the process in the end of the user data recording onlayer 0. The recording is performed in the following order.

1) Data area (to the end PSN of Layer 0)

2) Outer Guard track zone (Layer 0, padded)

3) L-RMZ.

FIG. 129A shows the process of the user data recording on Layer 1. Therecording is performed in the following order.

1) Drive test zone (Layer 1)

2) Outer Guard track zone (Layer 1, padded)

3) L-RMZ

4) Data area (Layer 1)

5) Drive test zone (Layer 1)

6) Data area (layer 1)

7) L-RMZ

Note that 5) to 7) are repeated by X times.

FIG. 129B shows the process in the end of the user data recording onLayer 1. The recording is performed in the following order.

1) Data area (to the end PSN of Layer 1)

2) Drive test zone (Layer 0, padded)

3) L-RMZ (padded)

4) R-Physical format information zone

5) Reference code zone

FIG. 129C shows a status of the Finalized disc. Inner Guard track zoneon Layer 1 is finally padded.

(Physical Sector Layout)

Each PS block contains 32 Physical sectors. On an HD DVD-R for duallayer disc, Physical sector numbers (PSN) of the Layer 0 continuouslyincreases in System Lead-in area and increases continuously from thebeginning of the Data Lead-in area to the end of the Middle area.However, PSN of the Layer 1 takes the bit-inverted value to that of theLayer 0 and continuously increases from the beginning of the Middle area(outside) to the end of the Data Lead-out area (inside) and increasescontinuously from the outer side of the System Lead-out area to theinner side of the System Lead-out area.

The bit-inverted number is calculated so that the bit value of ONEbecomes that of ZERO and vice versa. Physical sectors on each layer withbit-inverted PSNs to each other are at almost the same distance from thecenter of the disc.

The Physical sector whose PSN is X is contained in the PS block whose PSblock address is calculated by dividing X by 32, rounding off fractions.

The PSNs in the System Lead-in area are calculated by letting thePhysical sector placed at the end of the System Lead-in area be “131071”(01 FFFFh).

The PSNs in the Layer 0 except for the System Lead-in area arecalculated by letting the PSN of the Physical sector placed at thebeginning of the Data area located after the Data Lead-in area be“262144” (04 0000h). The PSNs on the Layer 1 except for the SystemLead-out area are calculated by letting the PSN of the Physical sectorplaced at the beginning of the Data area located after the Middle areabe “9184256” (8C 2400h).

Physical Segment Structure

The Data Lead-in area, Data area, Middle area and Data Lead-out areacomprise Physical segments. A Physical segment is specified withPhysical segment order and PS block address.

WAP Layout

The Physical segment is aligned with Wobble Address in Periodic position(WAP) information modulated in the wobble. Each WAP information isindicated with 17 Wobble Data Unit (WDU). The length of Physical segmentis equal to the length of 17 WDU. The layout of WAP is shown in FIG. 131which corresponds to FIGS. 72C and 72D for the single-sided single layerdisc. The numbers in a field of a WAP layout indicate the WDU number inPhysical segment. The first WDU in the Physical segment is 0.

In the WAP, b0 to b8 describe CRC, and b9 to b11 describe physicalsegment orders, and b12 to b30 describe PS block addresses, and b31 tob32 describe segment information. Among the segment information, b31describes a reserved area, and b32 describes a type. A type denotes atype of a physical segment (0b is type 1 (FIG. 74B), and 1b is type 2(FIG. 74C) or type 3 (FIG. 74D). The PS block addresses are assigned tothe respective PS blocks. With respect to the physical segment orders,000b is set to the first physical segment in the PS block, and physicalsegment orders are assigned to the other six types of physical segmentsin the same way.

Wobble Data Unit

Wobble Data Unit (WDU) is consists of 84 wobbles. The period of wobblesis equal to 93 T, where T denotes channel clock period. Primary WDU inSYNC field is shown in FIG. 132.

Primary WDU in Address field is shown in FIG. 133. 3 bits is recorded inthe Address field with 0b as Normal Phase Wobble (NPW) and 1b as InvertPhase Wobble (IPW).

Secondary WDU in SYNC field is shown in FIG. 134.

Secondary WDU in Address field is specified in FIG. 135. 3 bits isrecorded in the Address field with 0b as Normal Phase Wobble (NPW) and1b as Invert Phase Wobble (IPW).

WDU in Unity field is shown in FIG. 136. WDU for Unity field is notmodulated.

Modulation Rules of Bit

NPW and IPW are recorded on the track in the waveforms shown in FIG. 70.The start position of the physical segment coincides with the startposition of the SYNC field.

There are two possible modulated wobble positions, Primary WDU andSecondary WDU are shown in FIGS. 132 to 135. Normally the Primary WDU isselected. However, during the mastering process it is possible thatthere will already be a modulated wobble in the adjacent track. In sucha case, the Secondary WDU is selected to prevent from positioning themodulated wobble side by side, as shown in FIG. 73. Physical segmentsare categorized by the modulated wobble positions, called Type1, Type2and Type3, as shown in FIG. 74.

Type of Physical segment is selected according to the following rules.

1) Type1 or Type2 Physical segment is repeated equal to or more than 10times successively.

2) Type2 Physical segment is not repeated more than 28 timessuccessively.

3) Type3 Physical segment is selectable once at the transferringposition from Type1 Physical segment to Type2 Physical segment.

4) Modulated wobble positions is separated more than 2 wobble lengthfrom one of the adjacent track.

Lead-In Area, Lead-Out Area and Middle Area

The schematic of the Lead-in area and the Lead-out area is shown in FIG.137. The system lead-in area is composed of an initial zone, a bufferzone, a control data zone, and a buffer zone in sequence from the innerperipheral side. The connection area is composed of a connection zoneand a blank zone in sequence from the inner peripheral side. The datalead-in area is composed of a guard track zone, a drive test zone, adisc test zone, a blank zone, an RMD duplication zone, a recordingmanagement zone in the data lead-in area (L-RMD), an R-physical formatinformation zone, and the reference code zone in sequence from the innerperipheral side.

The details of the system lead-in area will be described. The initialzone contains embossed data segments. The main data of the data framerecorded as the data segment of the initial zone is set to “00h”.

The buffer zone consists of 1024 Physical sectors from 32 Data segments.The Main data of the Data frames eventually recorded as Data segments inthis zone is set to “00h”.

The Control data zone contains embossed Data segments. The Data segmentscontains embossed Control data. The Control data is comprised of 192Data segments starting from PSN 123904 (01 E400h). The structure of aControl data zone is shown in FIG. 138.

The structure of a Data segment in a Control data section is shown inFIG. 139. The contents of the first Data segment in a Control datasection is repeated 16 times. The first Physical sector in each Datasegment contains the physical format information. The second Physicalsector in each Data segment contains the disc manufacturing information.The third Physical sector in each Data segment contains the copyrightprotection information. The contents of the other Physical sectors ineach Data segment are reserved for system use.

The structure of the physical format information included in the controldata section is shown in FIGS. 140 to 142.

The explanation of the function of each Byte Position is describedbelow. The value specified for the Read power, Recording speeds,Reflectivity of Data area, Push-pull signal and On track signal given inBP 132-154 is only for example. Their actual values are decided by thedisc manufacture provided that the values are chosen within the valuessatisfying the emboss condition and the recorded user datacharacteristics.

The details of the data area allocation given in BP 4-15 are shown inFIG. 143. BP149 and BP152 specify reflectance ratios of the data areasof Layer 0 and Layer 1. For example, 0000 1010b denotes 5%. An actualreflectance ratio is specified by the following formula.Actual reflectance ratio=value×(1/2)

BP150 and BP153 specify push-pull signals of Layer 0 and Layer 1. Bit b7specifies a track shape of the disc of each layer. Bits b6 to b0 specifyamplitudes of the push-pull signals.

Track shape: 0b (track on a groove)

1b (track on a land) p Push-pull signal: for example, 010 1000b denotes0.40.

An actual amplitude of a push-pull signal is specified by the followingformula.Actual amplitude of push-pull signal=value×(1/100)

BP151 and BP154 specify amplitudes of on-track signals of Layer 0 andLayer 1.

On-track signal: for example, 0100 0110b denotes 0.70.

An actual amplitude of an on-track signal is specified by the followingformula.Actual amplitude of on-track signal=value×(1/100)

Connection Area on Layer 0

The Connection area on Layer 0 is intended to connect the System Lead-inarea and the Data Lead-in area. The distance between the centerlines ofthe end Physical sector of the System Lead-in area, of which PSN is 01FFFFh, and the centerlines of the start Physical sector of the DataLead-in area, of which PSN is 02 6B00h, is 1.36 μm to 5.10 μm. If thedisc is a single layer disc, the upper limit of the distance is 10.20μm. This is because the interlayer crosstalk is present in the duallayer. It is preferable for the dual layer disc that the distance issmall. Connection area does not have any embossed pits or grooves.

Data Lead-In Area

The Data segments of the Blank zone do not contain data. The Datasegments of the Guard track zone are filled with 00h before recording onLayer 1. The Disc test zone is intended for quality tests by the discmanufacture. The Drive test zone is intended for tests by a drive. Thiszone is recorded from the outer PS block to the inner PS block. All theData segments of this zone are recorded before finalizing the disc.

RMD Duplication Zone

The RMD duplication zone consists of a RDZ Lead-in, as shown in FIG.144. The RDZ Lead-in is recorded before recording the first RMD in theL-RMZ. The other fields of the RMD duplication zone are reserved andfilled with 00h. The size of the RDZ Lead-in is 64 kB and consists ofthe System Reserved Field (48 kB) and the Unique Identifier (ID) Field(16 kB). The data in the System Reserved Field is set to 00h, and theUnique ID Field consists of eight units which have the same 2 kB sizeand contents. The byte assignment of each unit includes the drivemanufacture ID, Serial number, Model number, and Unique Disc ID.

The Recording management zone in Data Lead-in area (L-RMZ) is recordedfrom PSN 03 CE00h to 03 FEFFH. The Recording management zone (RMZ)consists of Recording management data (RMD). The unrecorded part ofL-RMZ is recorded with the current RMD before finalizing the disc.

The Recording Management Data (RMD) contains the information about therecording on the disc. The size of the RMD is 64 kB. The data structureof RMD is shown in FIG. 145. Each RMD is formed of the main data of 2048bytes and recorded by a predetermined signal processing.

The RMD field 0 specifies general information of the disc, and thecontents of this field are shown in FIG. 146.

As a disc status of BP2,

00h: denotes that the disc is empty.

02h: denotes that the disc is recorded and not finalized.

03h: denotes that the disc is finalized.

08h: denotes that the disc is in a recording mode U.

11h: denotes that format operation is in progress. The others arereserved.

The details of the layout of data area allocation of BP22 to BP33 areshown in FIG. 147.

The details of the layout of renewed data area allocation of BP34 toBP45 are shown in FIG. 148.

The respective bits in a padding status of BP46 to 47 show thefollowings.

b15 . . . 0b: denotes that the inner guard track zone on Layer 0 is notpadded.

1b: denotes that the inner guard track zone on Layer 0 is padded.

b14 . . . 0b: denotes that the inner drive test zone on Layer 0 is notpadded.

1b: denotes that the inner drive test zone on Layer 0 is padded.

b13 . . . 0b: denotes that the RMD duplication zone is not padded.

1b: denotes that the RMD duplication zone is padded.

b12 . . . 0b: denotes that the reference code zone is not padded.

1b: denotes that the reference code zone is padded.

b11 . . . 0b: denotes that the outer guard track zone on Layer 0 is notpadded.

1b: denotes that the outer guard track zone on Layer 0 is padded.

b10 . . . 0b: denotes that the outer drive test zone on Layer 0 is notpadded.

1b: denotes that the outer drive test zone on Layer 0 is padded.

b9 . . . 0b: denotes that the extra guard track zone on Layer 0 is notpadded, or not assigned.

1b: denotes that the extra guard track zone on Layer 0 is padded.

b8 . . . 0b: denotes that the extra drive test zone on Layer 0 is notpadded, or not assigned.

1b: denotes that the extra drive test zone on Layer 0 is padded.

b7 . . . 0b: denotes that the outer guard track zone on Layer 1 is notpadded.

1b: denotes that the outer guard track zone on Layer 1 is padded.

b6 to b5 . . . 00b: denotes that the recording of Terminator is notstarted.

01b: denotes that the recording of Terminator is in progress.

10b: denotes reserved.

11b: denotes that the recording of Terminator is finished.

The details of the layout of drive test zone of BP52 to BP99 are shownin FIG. 149.The RMD Field1 contains the OPC related information. In theRMD Field1 it is possible to record the OPC related information for upto 4 drives that may coexist in a system, as shown in FIGS. 150 and 151.

In the case of a single drive, the OPC related information is recordedin the field #1 and the other fields are set to “00h. In every case, theunused fields of the RMD Field1 are set to 00h. The OPC relatedinformation of the present drive is always recorded in the filed #1. Ifthe field #1 of the current RMD does not contain the present driveinformation, which consists of Drive manufacturer ID, Serial number andModel number, the information in the field #1 to #3 of the current RMDis copied to the field #2 to #4 of the new RMD and the information inthe field #4 of the current RMD is discarded. If the field #1 of thecurrent RMD contains the present drive information, the information inthe field #1 is updated and the information of the other fields iscopied to the field #2 to #4 of the new RMD.

Inner Drive test zone address for Layer 0 of BP72 to BP75, BP328 toBP331, BP584 to BP587, and BP840 to BP843:

These fields specify minimum PS block address of the drive test zone inthe data lead-in area onto which the most recent power calibration hasbeen carried out. When a current drive does not carry out powercalibration in the inner drive test zone of Layer 0, the inner drivetest zone address of Layer 0 of the current RMD is copied to the innerdrive test zone address of a new RMD. When these fields are set to“00h”, this test zone is not used.

Outer Drive test zone address for Layer 0 of BP76 to BP79, BP332 toBP335, BP588 to BP591, and BP844 to BP847:

These fields specify minimum PS block address of the drive test zone inthe middle area of Layer 0 onto which the most recent power calibrationhas been carried out. When a current drive does not carry out powercalibration in the outer drive test zone of Layer 0, the outer drivetest zone address of Layer 0 of the current RMD is copied to the outerdrive test zone address of a new RMD. When these fields are set to“00h”, this test zone is not used.

Test zone usage descriptors of BP106, BP362, BP618, and BP874:

These fields specify descriptors for use of the four test zones. Therespective bits are assigned as follows.

b7 to b6 . . . Reserved areas.

b5 . . . 0b: The drive did not use the Extra drive test zone on Layer 0.

1b: The drive used the Extra drive test zone on Layer 0.

b4 . . . 0b: The drive did not use the Extra drive test zone on Layer 1.

1b: The drive used the Extra drive test zone on Layer 1.

b3 . . . 0b: The drive did not use the inner drive test zone on Layer 0.

1b: The drive used the inner drive test zone on Layer 0.

b2 . . . 0b: The drive did not use the outer drive test zone of Layer 0.

1b: The drive used the outer drive test zone on Layer 0.

b1 . . . 0b: The drive did not use the inner drive test zone on Layer 1.

1b: The drive used the inner drive test zone on Layer 1.

b0 . . . 0b: The drive did not use the outer drive test zone on Layer 1.

1b: The drive used the outer drive test zone on Layer 1.

Inner Drive test zone address of Layer 1 of BP108 to BP111, BP364 toBP367, BP620 to BP623, and BP876 to BP879:

These fields specify minimum PS block address of the drive test zone inthe data lead-out area onto which the most recent power calibration hasbeen carried out. When a current drive does not carry out powercalibration in the inner drive test zone of Layer 1, the inner drivetest zone address of Layer 1 of the current RMD is copied to the innerdrive test zone address of a new RMD. When these fields are set to“00h”, this test zone is not used.

Outer Drive test zone address of Layer 1 of BP112 to BP115, BP368 toBP371, BP624 to BP627, and BP880 to BP883:

These fields specify minimum PS block address of the drive test zone inthe middle area of Layer 1 onto which the most recent power calibrationhas been carried out. When a current drive does not carry out powercalibration in the outer drive test zone of Layer 1, the outer drivetest zone address of Layer 1 of the current RMD is copied to the outerdrive test zone address of a new RMD. When these fields are set to“00h”, this test zone is not used.

The RMD field 2 specifies data for user's exclusive use. When this fieldis not used, “00h” is set into the field. BP0 to BP2047 are fields whichcan be used for data for user's exclusive use.

All the bytes of the RMD field 3 are reserved, and are set to “00h”.

The RMD field 4 specifies information of R zones. The contents of thisfield are shown in FIG. 152. A portion of the data area reserved inorder to record user data is called R zone. R zone can be classifiedinto two types in accordance with a recording condition. In an Open Rzone, data can be added. In a Complete R zone, user data cannot beadded. In a data area, three or more Open R zones cannot be provided. Aportion of the data area which is not reserved for recording data iscalled Invisible R zone. An area following R zone can be reserved in theInvisible R zone. When data cannot be further added, there are noInvisible R zone.

The number of Invisible R zones of BP0 to BP1 is a total number of theInvisible R zones, the Open R zones, and the Complete R zones.

The RMD field 5 to the RMD field 21 specify information of R zones. Thecontents of these fields are shown in FIG. 153. When these fields arenot used, all of those are set to “00h”.

The R physical format information zone in the data lead-in area isstructured from seven PS blocks (224 physical sectors) beginning at PSN261888 (03 FF00h). The contents of the first PS block in the R physicalformat information zone are repeated seven times. The configuration ofthe PS block in the R physical format information zone is shown in FIG.154.

The contents of the physical format information in the data lead-in areaare shown in FIG. 155. FIG. 155 is the same as FIG. 140 showing thecontents of the physical format information in the system lead-in area.BP0 to BP3 are copied from the physical format information in the systemlead-in area. The layout of the data area allocation of BP4 to BP15 isdifferent from that of FIG. 143, and is shown in FIG. 156. BP16 toBP2047 are copied from the physical format information in the systemlead-in area.

(Middle Area)

The structure of the Middle area is changed by the Middle areaexpansion. The schematics of the Middle area before and after theexpansion are shown in FIGS. 157A and 157B. The structure of the Middlearea before the expansion is shown in FIG. 158. The size of the Guardtrack zone after the expansion and the creation of the Extra Guard trackzone on Layer 0 and the Extra Drive test zone depend on the end PSN ofthe Data area on Layer 0. The values Y and Z, which are the numbers ofPhysical sectors in the Guard track zone, are specified in FIG. 160.

Guard Track Zone

The Data segments of the Guard track zone on Layer 0 are filled with 00hbefore recording on Layer 1. The Data segments of the Guard track zoneon Layer 1 are filled with 00h before finalizing the disc.

Drive Test Zone

This zone is intended for tests by a drive. This zone on Layer 0 isrecorded from the outer PS block to the inner PS block. All the Datasegments of the Drive test zone on Layer 0 may be filled with 00h beforerecording on Layer 1.

Disc Test Zone

This zone is intended for tests by a disc manufacturer.

Blank Zone

The Data segments of the Blank zone do not contain data. The size of theoutermost Blank zone on Layer 0 is more than 968 PS blocks. The size ofthe outermost Blank zone on Layer 1 is more than 2464 PS blocks.

Structure of the Lead-Out Area

The structure of the Lead-out area is shown in FIG. 161.

The Data lead-out area is composed of a guard track zone, a drive testzone, a disk test zone, and a blank zone, in sequence from the outerperipheral side. The system lead-out area is composed of a systemlead-out zone.

Data segments of the guard track zone are filled with 00h beforefinalizing the disc.

The drive test zone is intended for tests by a drive. This zone isrecorded from the outer PS block to the inner PS block. Data segments ofthe blank zone do not contain data.

Connection Area on Layer 1

The Connection area on Layer 1 is intended to connect the Data Lead-outarea and the System Lead-out area. The distance between the centerlinesof the end Physical sector of the Data Lead-out area and the centerlinesof the start Physical sector of the System Lead-out area, of which PSNis FE 0000h, is 1.36 μm to 5.10 μm. Connection area does not have anyembossed pits or grooves.

All the main data of the data frame recorded as the physical sectors inthe System lead-out area are set to 00h.

Data Recording

Data is recorded on a disc according to the recording processesdescribed in this section

Single RZone Recording

Single RZone recording is a simple recording process. All the unrecordedData area is regarded as an RZone, and data is recorded from only onerecording point as shown in FIG. 162A.

Reserve RZone Recording

Reserve RZone recording enables to record data from plural recordingpoints. Data can be recorded from 3 or less recording points byreserving RZone which is located on Layer 0. In the case of reservingRZone, the capacity of the Data area is scaled down in order to preventthe influence of Layer 0 as shown in FIG. 163. The value (M-1) denotesthe end PSN of the Reserved RZone. The bit-inverted value of (M+A_(M))denotes the end PSN of the Data area. The information of the RMD Field4is updated by reserving RZone.

Mode U (User Specific Recording)

Mode U is prepared for a drive specific recording. After finalizing thedisc, the disc is compatible with a disc which is finalized afterSingle/Reserve RZone recording.

Formatting

Middle Area Expansion

Before recording in the Middle area on Layer 0, the Middle areaexpansion can be executed. The Middle area expansion enlarges the Middlearea and shrinks the Data area at the same time. The default end PSN ofthe Data area on Layer 0 is 73 DBFFh and the default start PSN of theData area on Layer 1 is 8C 2400h. Before recording in the Middle area onLayer 0, the drive can reassign a PSN, which is less than 73 DBFFh, tothe new end PSN of the Data area on Layer 0. The RMD Field0 is updatedby the Middle area expansion, and the new end PSN of the Data area onLayer 0 is recorded in the R-Physical format information zone, exceptthe Data area is relocated at finalization.

When the Middle area expansion is executed and the end PSN of the Dataarea on Layer 0 becomes X (<73 DBFFh), the bit-inverted number of X isthe start PSN of the Data area on Layer 1. The guard track zone, thedrive test zone, and the blank zone are relocated as shown in FIGS. 157Aand 157B.

Requirement Prior to Recording on Layer 1

Before recording on Layer 1, the guard track zone on Layer 0, which islocated in the data lead-in area and middle area is filled with 00h inorder to prevent the influence (interlayer crosstalk) of the Layer 0.The drive test zone on Layer 0 within the middle area may be filled with00h. When these zones are filled with 00h, the information on the RMDfield0 is renewed.

Finalization

When the Data area is finalized, the Terminator is recorded in theunrecorded Data area, as shown in FIG. 164. Main data of the Terminatoris set to 00h, and the area type of it is the Data Lead-out attribute.In the case that user data are recorded on Layer 1, the Terminator isrecorded on all the unrecorded Data area.

In the case that user data are not recorded on Layer 1, the Terminatoris recorded on Layer 0 and Layer 1, as shown in FIGS. 165A and 165B. TheTerminator on Layer 0 is contiguously recorded from the end of the Dataarea. If there are amply unrecorded Data segments between the Data areaand the Middle area, then it is not necessary to record the Terminatoron all of them and it is permitted to create the Drive test zone onLayer 1, as shown in FIG. 165A. The size of the drive test zone is 480PS blocks. The end PSN of the Terminator on Layer 0 and the start PSN ofthe Terminator on Layer 1 are specified in FIG. 166.

After recording the Terminator, the Guard track zones on Layer 1, whichare located in the Data Lead-out area and Middle area are filled with00h, if they are unrecorded. Before the Guard track zone which islocated in the Data Lead-out area is filled, the Drive test zone, theunrecorded part of the L-RMZ, the R-physical format information zone andthe Reference code zone which are located in the Data Lead-in area arerecorded.

If unrecorded data segment is present between the end PSN of theTerminator and the Middle area on Layer 0 as shown in FIG. 165B, it isunnecessary to record the Guard track zones which are located in theMiddle area on Layer 0 and Layer 1.

Conditions for measuring actuating signals of data lead-in area, dataarea, middle area, and data lead-out area

An offset canceller bandwidth is made to spread as compared with asingle layer as follows.

−3 dB closed-loop bandwidth: 20.0 kHz

The bandwidth is 5 kHz in a single layer. However, the bandwidth is madeto spread in order to provide margin.

Burst Cutting Area Code (BCA-Code)

The BCA is an area for recording information after the completion of thedisc manufacturing process. It is permitted to write the BCA-Codethrough the replication process using pre-pits, if the read-out signalsatisfies the BCA-Code signal specification. The BCA exists on the Layer1 of a single-sided dual layer disc. Since the BCA exists on Layer 1 ofa single-sided dual layer read-only disc, the drive can be compatiblewith the recordable layer disc and the read-only disc.

Measuring method of the channel bit length

Channel bit length is averaged over the whole disc. The following is oneof the methods for measuring the channel bit length averaged over thewhole disc.

In this method, 5 data points are measured. One is the averaged trackpitch. This value may be measured by using a He—Ne laser diffracted bythe tracks. The rests are: the number of Data segments (N_(d1)) betweenS_(n0) and S_(n1), the number of Data segments (N_(d2)) between S_(n0)and S_(n2), the number of track (n1) between S_(n0) and S_(n2), and thenumber of tracks (n2) between S_(n1) and S_(n2), as shown in FIG. 167.S_(n0) is the starting point of a Data segment in the inner radius.S_(n1) is the starting point of a Data segment in the intermediateradius. S_(n2) is the starting point of a Data segment in the outerradius.

The measuring drive rotates the measuring disc as slowly as possible tomaintain the accuracy of the number of tracks and the Data segments. CBLis calculated using equation (5) shown below. $\begin{matrix}{\frac{\left. {{\pi\left\{ \left( {r_{0} + {\Delta\quad r_{0}} + {n_{1}{Tp}}} \right)^{2} \right)} - \left( {r_{0} + {\Delta\quad r_{0}}} \right)^{2}} \right\}}{Tp} = {LN}_{d\quad 1}} & (1) \\{{{\pi\quad n_{1}{Tp}} + {2{\pi\left( {r_{0} + {\Delta\quad r_{0}}} \right)}}} = \frac{{LN}_{d\quad 1}}{n_{1}}} & (2) \\{similarly} & \quad \\{{{{\pi\left( {n_{1} + n_{2}} \right)}{Tp}} + {2{\pi\left( {r_{0} + {\Delta\quad r_{0}}} \right)}}} = \frac{{LN}_{d\quad 2}}{n_{1} + n_{2}}} & (3) \\{(3) - (2)} & \quad \\{L = \frac{\pi\quad n_{2}{Tp}}{\frac{N_{d\quad 2}}{n_{1} + n_{2}} - \frac{N_{d\quad 1}}{n_{1}}}} & (4) \\{{CBL} = \frac{L}{CBNs}} & (5)\end{matrix}$

CBL: Channel bit length averaged over whole disc

CBNs: Number of channel bits in a Data segment

S_(n0): Starting point of a Data segment

r₀: Radius of the disc near S_(n1)

Δ_(r0): Measurement error

N_(d1): Number of Data segments between S_(n0) and S_(n1)

N_(d2): Number of Data segments between S_(n0) and S_(n2)

n1: Number of tracks between S_(n0) and S_(n1)

n2: Number of tracks between S_(n1) and S_(n2)

L: Averaged Data segment Length

Tp: Averaged track pitch

Update condition of RMD

RMD is updated in at least one of the following conditions;

1) At least one of the contents specified in RMD Field0 is changed, or

2) Drive test zone address specified in RMD Field1 is changed, or

3) Invisible RZone number, First Open RZone number or Second RZonenumber specified in RMD Field4 is changed, or

4) The difference between the PSN of the least recorded Physical segmentin RZone #i and “Least recorded PSN of RZone #i” registered in the leastRMD becomes larger than 37888.

Note: Updating RMD is not required as long as the sequence of datarecording operation is in process by an equal to or less than 4 PSblocks.

Guideline to select the type of Physical segment

The rules to select the type of Physical segment are described. Anexample of the procedure to observe the rules will be described.

FIGS. 169A, 169B, and 170 are made for tracks on Layer 0. For tracks onLayer 1, FIGS. 169A and 169B and FIG. 118 should be replaced with thefigures for Layer 1 in the same way as FIGS. 169A is replaced with FIGS.169B for Layer 1.

The principle of the procedure is described as follows.

The purpose of the type selection is to prevent from positioning themodulated wobble side by side.

A schematic of 2 adjacent tracks is shown in FIGS. 168A and 168B. Thestart point of the track #i is just the same as that of Physical segment#n, where i and n denote natural numbers. The track #i consists of jPhysical segments, k WDUs and m wobbles, where j denotes a naturalnumber and k and m denote non-negative integers. If both k and m are notzero, then the Physical segment #n+j locates in track #i and #i+1.

The relative position between the modulated wobbles in track #i and #i+1depends on m. If m is equal to or more than 21 and less than 63, thenType1 Physical segments should be selected in the track #i+1, as shownin FIG. 169A. Otherwise, Type2 Physical segments should be selected inthe track #i+1, as shown in FIG. 169B. For every case, Type1 Physicalsegments are selected in the track #i.

Type3 Physical segment is selectable once at the transferring positionfrom Type1 Physical segment to Type2 Physical segment. The selection ofType3 Physical segment depends on not only m but also k. An example ofthe case that Type3 Physical segment should be selected is shown in FIG.170. Type3 Physical segment should be selected in one of the followingconditions;

1) k is equal to or more than 6 and less than 12, and m is equal to ormore than 0 and less than 21, or

2) k is equal to or more than 5 and less than 11, and m is equal to ormore than 63 and less than 84.

A procedure for selecting a type of a physical segment is the same asthat of FIG. 110 according to the first embodiment. Repetitive processesin the procedure are executed for substantially two tracks. Therespective processes are shown hereinafter.

A length of the repetitive processes depends on the number of physicalsegments selected in the third step.

1) Estimation of the number of wobbles on one track (ST82)

Values of decimals of wobbles on a current track are estimated on thebasis of values on a previous track.

An integral value of wobble N_(W) can be obtained by rounding down thedecimals to an approximate value of an integer.

2) Calculation of j, k, and m (ST83)

j, k, and m are calculated as follows.j=N _(W)−(N _(W) mod 1428)/1428,m=N_(W) mod 84,k=((N _(W) −m)/84)mod 17

Operation “x” mod “y” denotes a modulus after dividing x by y.

3) Selection of a type (ST84)

A type of a physical segment is selected in accordance with theconditions of k and m as follows.

Condition 1: 21<m<63

2j physical segments of type 1 are selected.

Condition 2: 0<k<6 and 0<m<21, or 0<k and 63<m<84

j physical segments of type 1 and j physical segments of type 2 areselected.

Condition 3: 6<k<12 and 0<m<21, or 5<k<11 and 63<m<84

j physical segments of type 1, one physical segment of type 3, and jphysical segments of type 2 are selected.

Condition 4: 12<k<17 and 0<m<21, or 11<k<17 and 63<m<84

j+1 physical segments of type 1 and j+1 physical segments of type 2 areselected.

Light Fastness of the Disc

Light fastness of a disc is tested with an air-cooled Xenon lamp andtest apparatus complying with ISO-105-B02.

Test Conditions

Black Panel Temperature: <40° C.

Relative humidity: 70 to 80%

Disc Illumination:

Through the substrate, normal incident.

Write Power

The write power has four levels, Peak power, Bias power1, Bias power2and Bias power3. These are the optical powers incident on the read-outsurface of the disc and used for writing marks and spaces.

Peak power, Bias power1, Bias power2 and Bias power3 are given in theControl data zone. The maximum Peak power does not exceed 13.0 mW. Themaximum Bias power1, Bias power2 and Bias power3 do not exceed 6.5 mW.

The Peak power P_(rec) of Layer 1 which corresponds to the recorded areaof Layer 0 and the Peak power P_(unrec) of Layer 1 which corresponds tothe unrecorded area of Layer 0 satisfy the following requirements.

|P_(rec)−P_(unrec)|<10% of P_(unrec), and

P_(rec) and P_(unrec) do not exceed 13.0 mW.

Adaptive Write Control

To precisely control the mark edge position, the timings of the firstpulse, the last pulse and the mono pulse can be modulated.

Mark lengths of the NRZI signal are categorized as M2, M3 and M4. Marklengths of M2, M3 and M4 represent 2 T, 3 T and longer than 3 T,respectively.

Space lengths of the NRZI signal immediately before the mark arecategorized as LS2, LS3 and LS4. Space lengths of LS2, LS3 and LS4represent 2 T, 3 T and longer than 3 T, respectively.

Space lengths of the NRZI signal immediately after the mark arecategorized as TS2, TS3 and TS4. Space lengths of TS2, TS3 and TS4represent 2 T, 3 T and longer than 3 T, respectively.

T_(LC) can be modulated as a function of the category of the mark lengthof the NRZI. Therefore, T_(LC) can have three values, as follows.

T_(LC) (M2) T_(LC) (M3) T_(LC) (M4)

T_(LC) (M) represents the T_(LC) value when the category of the marklength of the NRZI signal is M. These three T_(LC) values are given inthe Control data zone.

T_(SFP) can be modulated as a function of the category of the marklength of the NRZI signal and the category of the space length of theNRZI signal immediately before the mark. Therefore, T_(SFP) can havenine values, as follows.

T_(SFP) (M2, LS2) T_(SFP ()M3, LS2) T_(SFP) (M4, LS2)

T_(SFP) (M2, LS3) T_(SFP) (M3, LS3) T_(SFP) (M4, LS3)

T_(SFP) (M2, LS4) T_(SFP) (M3, LS4) T_(SFP) (M4, LS4)

T_(SFP) (M, LS) represents the T_(SFP) value when the category of themark length of the NRZI signal is M and the category of the space lengthof the NRZI signal immediately before the mark is LS.

These nine T_(SFP) values are given in the Control data zone.

T_(ELP) can be modulated as a function of the category of the marklength of the NRZI signal and the category of the space length of theNRZI signal immediately after the mark. Therefore, T_(ELP) can have ninevalues, as follows.

T_(ELP) (M2, TS2) T_(ELP) (M3, TS2) T_(ELP) (M4, TS2)

T_(ELP) (M2, TS3) T_(ELP) (M3, TS3) T_(ELP) (M4, TS3)

T_(ELP) (M2, TS4) T_(ELP) (M3, TS4) T_(ELP) (M4, TS4)

T_(ELP) (M, TS) represents the T_(ELP) value when the category of themark length of the NRZI signal is M and the category of the space lengthof the NRZI signal immediately after the mark is TS.

These nine T_(ELP) values are given in the Control data zone.

The T_(LC) values for Layer 0 can be represented as the letters from aL0to cL0 as a function of the mark length. The T_(SFP) values for Layer 0can be represented as the letters from dL0 to IL0 as a function of themark length and the previous space length. The T_(ELP) values for Layer0 can be represented as the letters from mL0 to uL0 as a function of themark length and the trailing space length.

The T_(LC) values for Layer 1 can be represented as the letters from aL1to cL1 as a function of the mark length. The T_(SFP) values for Layer 1can be represented as the letters from dL1 to IL1 as a function of themark length and the previous space length. The T_(ELP) values for Layer1 can be represented as the letters from mL1 to uL1 as a function of themark length and the trailing space length. The T_(SFP) table, theT_(ELP) table and the T_(LC) table are shown in FIG. 171.

Conditions for writing data on Layer 1

The following conditions should be satisfied for writing data on Layer 1at disc testing, as shown in FIG. 172.

1) Layer 1 should be recorded through the recorded Layer 0 area.

2) The radial dimension of the area to be recorded on Layer 1 should besmaller than the recorded area on Layer 0 keeping the Clearance.

3) When the edge of the recorded area on Layer 0 is shifted byadditional recording, the edge of recording area on Layer 1 can beshifted corresponding to the amount of additional recording on Layer 0.

Note: It is recommended that Layer 0 should be recorded more than 0.5 mmin radial direction and Layer 1 should be recorded with the Clearance ofmore than 0.2 mm in radial direction from each edge of recorded Layer 0.The Clearance A in this Annex should be set to double value of theClearance Cl to perform the testing stably.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the inventions. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the inventions. For example, someconstituent elements may be deleted from all the constituent elementsshown in the embodiments. Further, the constituent elements across thedifferent embodiments may be properly combined with one another. Forexample, a structure of two recording layers may be applied to a dyebased recording film as shown in FIG. 2B. Specifically, the presentinvention may be applied to a single-sided multi-layered HD DVD-R discobtained by multi-layering two or more dye based recording films. Theaccompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of theinventions.

1. An information storage medium comprising: information layers of layer0 and layer 1 which are sequentially arranged from a read surface,recording is carried out from an inner periphery to an outer peripheryof layer 0, and recording is carried out from an outer periphery to aninner periphery of layer 1, wherein the information layer of layer 0comprises a system lead-in area, a data lead-in area, a data area, and amiddle area which are arranged from an inner periphery; the informationlayer of layer 1 comprises a system lead-out area, a data lead-out area,a data area, and a middle area which are arranged from an innerperiphery; an end position of the data area of layer 1 is positioned ata periphery outer than a start position of the data area of layer 0; thedata lead-in area comprises a guard track zone corresponding to a zonewhich is wider than a test zone in the data lead-out area; the datalead-out area comprises a guard track zone corresponding to a zone whichis wider than a test zone and a management zone in the data lead-inarea; the middle area of layer 0 comprises a guard track zonecorresponding to a zone which is wider than a test zone in the middlearea of layer 1; and the middle area of layer 1 comprises a blank zonecorresponding to a zone which is wider than a test zone in the middlearea of layer
 0. 2. An information storage medium comprising:information layers of layer 0 and layer 1 which are sequentiallyarranged from a read surface, recording is carried out from an innerperiphery to an outer periphery of layer 0, and recording is carried outfrom an outer periphery to an inner periphery of layer 1, wherein theinformation layer of layer 0 comprises a system lead-in area, a datalead-in area, a data area, and a middle area which are arranged from aninner periphery; the information layer of layer 1 comprises a systemlead-out area, a data lead-out area, a data area, and a middle areawhich are arranged from an inner periphery; an end position of the dataarea of layer 1 is positioned at an outer periphery by a clearancecorresponding to an interlayer crosstalk from a start position of thedata area of layer 0; the data lead-in area comprises a guard track zonecorresponding to a zone which is obtained by adding the clearance toboth sides of the a test zone in the data lead-out area; the datalead-out area comprises a guard track zone corresponding to a zone whichis obtained by adding the clearance to both sides of a test zone and amanagement zone in the data lead-in area; the middle area of layer 0comprises a guard track zone corresponding to a zone which is obtainedby adding the clearance to both sides of a test zone in the middle areaof layer 1; and the middle area of layer 1 comprises a blank zonecorresponding to a zone which is obtained by adding the clearance toboth sides of a test zone in the middle area of layer
 0. 3. Theinformation storage medium according to claim 2, wherein the clearanceis a sum of a radius on another layer of a light beam focused on alayer, a radial error in a same track between layer 0 and layer 1, andan average value of shifts of a track shape from a complete round. 4.The information storage medium according to claim 3, wherein the radiusof the light beam on the other layer is 10 μm, the radial error is 40μm, and the average value of shifts from the complete round is 50 μm. 5.The information storage medium according to claim 2, wherein themanagement zone in the data lead-in area comprises a recordingmanagement zone.
 6. An information recording method for recordinginformation on an information storage medium comprising informationlayers of layer 0 and layer 1 which are sequentially arranged from aread surface, recording is carried out from an inner periphery to anouter periphery of layer 0, and recording is carried out from an outerperiphery to an inner periphery of layer 1, wherein the informationlayer of layer 0 comprises a system lead-in area, a data lead-in area, adata area, and a middle area which are arranged from an inner periphery;the information layer of layer 1 comprises a system lead-out area, adata lead-out area, a data area, and a middle area which are arrangedfrom an inner periphery; an end position of the data area of layer 1 ispositioned at an outer periphery by a clearance corresponding to aninterlayer crosstalk from a start position of the data area of layer 0;the data lead-in area comprises a guard track zone corresponding to azone which is obtained by adding the clearance to both sides of the atest zone in the data lead-out area; the data lead-out area comprises aguard track zone corresponding to a zone which is obtained by adding theclearance to both sides of a test zone and a management zone in the datalead-in area; the middle area of layer 0 comprises a guard track zonecorresponding to a zone which is obtained by adding the clearance toboth sides of a test zone in the middle area of layer 1; and the middlearea of layer 1 comprises a blank zone corresponding to a zone which isobtained by adding the clearance to both sides of a test zone in themiddle area of layer 0, the information recording method comprising:recording information on the data area of layer 0 before recording ontothe data area of layer 1; recording information from the inner peripheryto the outer periphery on the data area of layer 0; and recordinginformation from the outer periphery to the inner periphery on the dataarea of layer
 1. 7. An information reproducing apparatus whichreproduces information from an information recording medium comprisinginformation layers of layer 0 and layer 1 which are sequentiallyarranged from a read surface, recording is carried out from an innerperiphery to an outer periphery of layer 0, and recording is carried outfrom an outer periphery to an inner periphery of layer 1, wherein theinformation layer of layer 0 comprises a system lead-in area, a datalead-in area, a data area, and a middle area which are arranged from aninner periphery; the information layer of layer 1 comprises a systemlead-out area, a data lead-out area, a data area, and a middle areawhich are arranged from an inner periphery; an end position of the dataarea of layer 1 is positioned at an outer periphery by a clearancecorresponding to an interlayer crosstalk from a start position of thedata area of layer 0; the data lead-in area comprises a guard track zonecorresponding to a zone which is obtained by adding the clearance toboth sides of the a test zone in the data lead-out area; the datalead-out area comprises a guard track zone corresponding to a zone whichis obtained by adding the clearance to both sides of a test zone and amanagement zone in the data lead-in area; the middle area of layer 0comprises a guard track zone corresponding to a zone which is obtainedby adding the clearance to both sides of a test zone in the middle areaof layer 1; and the middle area of layer 1 comprises a blank zonecorresponding to a zone which is obtained by adding the clearance toboth sides of a test zone in the middle area of layer 0, the reproducingapparatus comprising: means for reproducing management information aboutrecording position of each zone from the system lead-in area and thedata lead-in area; and means for reproducing information from the dataarea based on the management information.
 8. An information recordingapparatus which records information on an information storage mediumcomprising information layers of layer 0 and layer 1 which aresequentially arranged from a read surface, recording is carried out froman inner periphery to an outer periphery of layer 0, and recording iscarried out from an outer periphery to an inner periphery of layer 1,wherein the information layer of layer 0 comprises a system lead-inarea, a data lead-in area, a data area, and a middle area which arearranged from an inner periphery; the information layer of layer 1comprises a system lead-out area, a data lead-out area, a data area, anda middle area which are arranged from an inner periphery; an endposition of the data area of layer 1 is positioned at an outer peripheryby a clearance corresponding to an interlayer crosstalk from a startposition of the data area of layer 0; the data lead-in area comprises aguard track zone corresponding to a zone which is obtained by adding theclearance to both sides of the a test zone in the data lead-out area;the data lead-out area comprises a guard track zone corresponding to azone which is obtained by adding the clearance to both sides of a testzone and a management zone in the data lead-in area; the middle area oflayer 0 comprises a guard track zone corresponding to a zone which isobtained by adding the clearance to both sides of a test zone in themiddle area of layer 1; and the middle area of layer 1 comprises a blankzone corresponding to a zone which is obtained by adding the clearanceto both sides of a test zone in the middle area of layer 0, theinformation recording apparatus comprising: a recording unit whichrecords information on the data area of layer 0 before recording ontothe data area of layer 1; a recording unit which records informationfrom the inner periphery to the outer periphery on the data area oflayer 0; and a recording unit which records information from the outerperiphery to the inner periphery on the data area of layer
 1. 9. Aninformation reproducing method for reproducing information from aninformation recording medium comprising information layers of layer 0and layer 1 which are sequentially arranged from a read surface,recording is carried out from an inner periphery to an outer peripheryof layer 0, and recording is carried out from an outer periphery to aninner periphery of layer 1, wherein the information layer of layer 0comprises a system lead-in area, a data lead-in area, a data area, and amiddle area which are arranged from an inner periphery; the informationlayer of layer 1 comprises a system lead-out area, a data lead-out area,a data area, and a middle area which are arranged from an innerperiphery; an end position of the data area of layer 1 is positioned atan outer periphery by a clearance corresponding to an interlayercrosstalk from a start position of the data area of layer 0; the datalead-in area comprises a guard track zone corresponding to a zone whichis obtained by adding the clearance to both sides of the a test zone inthe data lead-out area; the data lead-out area comprises a guard trackzone corresponding to a zone which is obtained by adding the clearanceto both sides of a test zone and a management zone in the data lead-inarea; the middle area of layer 0 comprises a guard track zonecorresponding to a zone which is obtained by adding the clearance toboth sides of a test zone in the middle area of layer 1; and the middlearea of layer 1 comprises a blank zone corresponding to a zone which isobtained by adding the clearance to both sides of a test zone in themiddle area of layer 0, the reproducing method comprising: reproducingmanagement information about recording position of each zone from thesystem lead-in area and the data lead-in area; and reproducinginformation from the data area based on the management information.